Vinyl carbanions

Item Type text; Dissertation-Reproduction (electronic)

Authors Newton, David John, 1941-

Publisher The University of Arizona.

Rights Copyright © is held by the author. Digital access to this materialis made possible by the University Libraries, University of Arizona.Further transmission, reproduction or presentation (such aspublic display or performance) of protected items is prohibitedexcept with permission of the author.

Download date 06/07/2021 12:31:50

Link to Item http://hdl.handle.net/10150/565177

http://hdl.handle.net/10150/565177

VINYL GARBANIONS

by-

David John Newton

, ©A D i s s e r t a t i o n Subm itted to th e F a c u l ty o f th e

DEPARTMENT OF CHEMISTRY

In P a r t i a l F u l f i l l m e n t of th e R equ irem en ts For th e Degree of

DOCTOR OF PHILOSOPHY

In th e G radua te C o llege

THE UNIVERSITY OF. ARIZONA

.1 9 6 8

THE UNIVERSITY OF ARIZONA

GRADUATE COLLEGE

I hereby recommend th a t t h i s d i s s e r t a t i o n prepared under my

d i r e c t i o n by David John Newton________________________

e n t i t l e d VINYL GARBANIONS

be a c c ep te d as f u l f i l l i n g th e d i s s e r t a t i o n requirem ent o f th e

degree o f _________________ DOCTOR OF PHILOSOPHY____________________

s e r t a t i o n D ir e c to r D a tyI ( . l i c i t

A f t e r i n s p e c t i o n o f the f i n a l copy o f th e d i s s e r t a t i o n , the

f o l l o w in g members o f th e F in a l Exam ination Committee concur in

i t s approval and recommend i t s a c c e p ta n c e :*

7

-rJVH6 %C, l?C// c u u

This approval and a c cep ta n ce i s c o n t in g e n t on the c a n d id a t e ' s adequate performance and d e fe n se o f t h i s d i s s e r t a t i o n a t the f i n a l o r a l ex a m in a t io n . The i n c l u s i o n o f t h i s s h e e t bound in to the l ib r a r y copy o f the d i s s e r t a t i o n i s e v id en ce o f s a t i s f a c t o r y performance a t the f i n a l exam in ation .

STATEMENT BY AUTHOR

T h is d i s s e r t a t i o n has been s u b m it ted in p a r t i a l f u l f i l l m e n t o f re q u i re m e n ts f o r an advanced d eg ree a t The U n iv e r s i t y o f A rizona and i s d e p o s i t e d in th e U n iv e r s i t y L ib ra ry to be made a v a i l a b l e to borrow e r s under r u l e s o f th e L i b r a r y 0

B r i e f q u o ta t i o n s from t h i s d i s s e r t a t i o n a re a l lo w a b le w i th o u t s p e c i a l p e rm iss io n ^ p ro v id ed t h a t a c c u r a t e acknowledgment of sou rce i s made0 R eq u es ts f o r p e rm is s io n f o r ex tended q u o ta t io n from or r e p r o d u c t io n of t h i s m a n u s c r ip t in whole or in p a r t may be g ra n te d by th e head of th e m ajo r d ep a r tm en t or th e Dean of th e G raduate C o llege when in h i s judgm ent th e p roposed u se o f th e m a t e r i a l i s in th e i n t e r e s t s of s c h o la r s h ip o In a l l o th e r i n s t a n c e s , how ever, p e rm is s io n m ust be o b ta in e d from th e a u t h o r G

SIGNED;- \Sl oxn-tl XoWvv.

To Lynn

i l l

ACKNOWLEDGMENT

The a u th o r w ish es to th a n k D r„ James E, Mulvaney f o r th e p a t i e n t

g u idance and h e l p f u l c o n t r i b u t i o n s g iv e n d u r in g th e c o u rs e o f t h i s r e

s e a r c h , Dr„ Lawrence J„ C arr f o r u s e f u l s u g g e s t io n s , and. th e A ir F o rce

O f f ic e of S c i e n t i f i c R ese a rc h (AFOSR) f o r f i n a n c i a l s u p p o r t o f t h i s

w ork.

TABLE OF CONTENTS

\ Page

■ AB STRACT " o © o © o o e o © o o 6 G © © o © e o e © 0 © e e o e o VI11' ' ' . . ■

INTRODUCTION e © G e © © © e < ) © © © o © e , © © © o o o e o e o o 1

R e a c t io n s o f O rg a n o li th iu m Compounds w i th A c e ty le n e s © © © © 1

R e a c t io n s of Organometa11i c Compounds w i th A c e ty le n e s -E xc lu d in g O rg a n o li th iu m Compounds © © © © © © © © © © © © © © 7

Use of T e r t i a r y Amines w i th O rg a n o m e ta l l ie Compounds 0 © e e 10

RESULTS AND DISCUSSION © © ©.© , © , © © © © © © © © © © © © © © 14

R e a c t io n s o f O rg a n o li th iu m Compounds and A ce ty le n e s in th e Absence of Added Amine © © © © © © © © © © © © © © © © 14

n - B u t y l l i t h i u m and DPA. © © © © © © © © © © © © © © © . © 14_t - Bu t y 11 i th ium and DPA © © © © © © © © © © © © © © © © © 17n - B u t y l l i t h i u m and l-P h e n y lp ro p y n e © © © © © © © © © © © 18

R e a c t io n s o f O rg an o li th iu m Compounds and A ce ty le n e s in th e P re se n c e o f N ,N pN * ,N *-T etram ethy le thy lene-d iam ine (THEDA) © ©..© © © © © © © © © © © © © © ® © © © © © © 20

Phenyl l i t h i u m and DPA © © © © © © © © © © © © © © © © © © 20n» Bu t y 11i th ium and DPA © © © © © © © © © © © © © © o © © 21t.-B u ty l l i t h i u m and DPA © © © © © © © © © © © © © © © © © 22n-Bu t y 11i th ium and 1 -PhenyIp r opyne e ©, © © © © © © © © © 31

The N a tu re of V in y l l i th iu m Compounds © © © © © © © © © © © © 33

C hem ically Induced Dynamic N u c lea r P o l a r i z a t i o n( C I D N P ) © e 0 © 0 © 0 0 © 0 0 G © 0 0 0 0 0 G 0 0 0 G © 0 0 0 42

EXPERIMENTAL © © © © © © © © © © © © © © © © © © © © © © © © © © 43

n - B u ty l l i t h iu m and DPA D e u te r o ly s i s © © © © © © © © © © © © © 45.In E th e r o o © © © © © © . © © © © © © © © © © © © © © © © 45In Hexane ̂ TMEDA © © © © © © © © © o . c © © © © © © © © © 4 6

L ith ium Deu t e r ox ide 9 D euterium Oxide, and DPA * ̂ © © © © ©. © 46

A nhydride of 2 -P h e n y l -3- (o y c a rb o x y p h e n y l)” 2 ~ h ep ten o ic Acid © 47

v

VI

TABLE OF CONTENTS— -Continued

'„ ■ . PaSe

J t - B u ty l l i t h iu m , . TMEDA? and DPA o e o o e e o o o o e c o o o 47 T e rm in a t io n o f R e a c t io n by C arb o n a t io n . . * . . . * * 47T e rm in a t io n o f R e a c t io n by D e u te r o ly s i s 0 o © e o c o 48T e rm in a t io n o f R e a c t io n by H y d ro ly s is . * . , * * * * , 50

Osmium T e t ro x id e ^ C a ta ly z e d P e r io d a t e O x id a t iv eC leavage o f D e u te ra te d B u t y l s t i l b e n e s 0 © c o © o © o © © o o 51

O x id a t iv e C leavage of D e u te ra te d b ra n s - oc-n-Bu ty I s t r lb ene -o o o © o © o o © © © © © © o © © © © © ©.© 51A ttem pted O x id a t iv e C leavage o f D e u te ra te d c i s - OL-1.-Bu ty I s t i lb ene © © © © . © © © © © © © © © © © © © © © 53

P o ta s s iu m Perm anganate O x id a t io n of D e u te ra te d c i s -o t t —Bu ty I s 11 lb ene o o a © © © © © © " © © © © © © © © © © 53

P h o to i s o m e r iz a t io n of " 4 ^4-Dimethy 1«2^3-d ip h e n y l - 2 - p e n te n o ic Acid © © © © © © © © . © © © © © © © © © © 54

R e a c t io n of a c i s - t r a n s M ix tu re of 4 p4 -D im ethy l-2 ,3~d ip h e n y l - 2 - p e n te n o ic Acid w i th T h io n y l C h lo r id e © © © © © © © 55

C y c lo d e h y d ra t io n o f B u t y l s t i l b e n e C a rb o x y l ic Acidsw i th S u l f u r i c Acid © o © © © © © © © © © © © © © © © . © © © © 55

R e a c t io n w i th c i s - 2 93 -D ip h e n y l -2 -h e p te n o ic Acid e © © © © 56R e a c t io n w i th t r a n s - 2 9 3 -D ip h e n y l -2 -h e p te n o ic Acid e © 0. ©■ 56R e a c t io n w i th c i s -4 g 4 -D im e th y l -2 g 3 -d ip h e n y l -2 -

p e n te n o ic A.c i d o © © © © © © © © © © © © © © © © © © 56R e a c t io n w i th a c i s - t r a n s M ix tu re of 4 , 4 -D im ethy1=

2 ,3 ~ d ip h e n y l - 2 - p e n te n o ic Acid 0 © © © © © © © © © © © 56

t - B u t y l l i t h i u m and DPA D e u te r o ly s i s o © © © © © © © © © © - © © 57

n - B u ty l l i t h iu m and 1 -P henylpropyne © © © © © © ; © © © © © © © ‘ 58R e a c t io n in Hexane o © © © © © © © © © © © © © © © © © © 58D e u te r o ly s i s o f R e a c t io n in Hexane? TMEDA 0 © © © © © © © 59

L ith ium D eu te rox ide? D euterium Oxide? and 3 -P h en y lp ro p y n e 0 © 59

L ith ium D eu te rox ide? D euterium Oxide? and 1 -Pheny lp ropyne 0' © 60

P h e n y l l i th iu m ? TMEDA? and DPA e © © © © © © © © © © © © © © © 60' T e rm in a t io n of th e R e a c t io n w i th D euterium Oxide © © © © 60

T e rm in a t io n o f th e R e a c t io n w i th D euterium C h lo r id e © © © 61

VI1TABLE OF CONTENTS— Continued

Page

T r ip h e n y l e th y le n e 5 TMEDAf and D euterium C h lo r id e 0 o o o e o. 62

B rom o tr ip h en y 1e t h y 1e n e 2 TMEDA? and L ith ium M etal c o p © © o 62R e a c t io n m E th e r ©. © c © © © e © © ©, © © © © © © © © © ©. 62T e rm in a t io n of R e a c t io n in Hexane w i th D euteriumOxide © © o o e e e o o e o e e e o c o o e e e o o o e e 63

LITERAfURE CITED © ©. © © © © © © © © © © © © © © © © © © © ©© © 64

ABSTRACT

A s tu d y was made of th e r e a c t i o n of d ip h e n y la c e ty le n e (DPA) and

v a r io u s o rg a n o l i th iu m compounds in th e p re s e n c e of N9N?Nf ~ t e t r a -

m e th y le th y le n e d ia m in e (TMEDA)0 I t was found t h a t r e a c t i o n s occu rred

much more r a p i d l y and , in .some c a s e s , more c l e a n ly w i th th e amine p r e s

e n t e

T rea tm en t o f 1*0 mole of DPA and 2*5 moles o f TMEDA w i th 2 e5

moles of n - b u t y l l i t h i u m in hexane gave on d e u t e r o l y s i s a 69% y ie ld of

d i d e u t e r a t e d "t r a n s - O C - n - b u t y f s t i l b e n e 0 S i m i l a r l y , a m ix tu re o f l e0

mole of DPA and 2*5 m oles o f a 1 :1 pheny l lithium-TMEDA complex in h ex

ane gave on t r e a tm e n t w i th d e u te r iu m o x i d e : a 63% y i e l d of d id e u te r a t e d

t r i p h e n y le t h y le n e e In b o th i n s t a n c e s , th e d eu te r iu m s w ere found to be

in c o rp o r a te d in th e v i n y l i c p o s i t i o n and in th e o r th o p o s i t i o n of th e

(X p h en y l g ro u p 0

D e u te r o l y s i s o f a r e a c t i o n m ix tu re c o n ta in in g l o0 mole of DPA,

2*5 moles of TMEDA, and 2*5 moles of t y b u t y l l i t h i u m in p en tan e y ie ld e d

m onodeu te fa ted c i s - and t r a n s - C X - t - b u ty l s t i lb e n e in a r a t i o of 6 :1 , r e

s p e c t iv e ly * C a rb o n a t io n o f th e r e a c t i o n m ix tu re gave a 41% y i e l d of

c i s - 4 ,4 ~ d i m e t h y l - 2 ,3 - d i p h e n y l - 2 - p e n t e n o ic a c id *

In a l l c a s e s i n w hich TMEDA was p r e s e n t in th e r e a c t i o n of o r

g a n o l i th iu m compounds w i th DPA, d e u te r iu m was found to be p r e s e n t to a

sm a l l e x t e n t in th e / 3 pheny l r i n g a f t e r t e r m in a t io n by d e u t e r o l y s i s 6

Two p o s s i b l e e x p la n a t io n s f o r t h i s w ere p r e s e n te d *

. . . "v i n

ixThe r e a c t i o n betw een t ~ b u t y l l i t h i u m and DBA a t 9 5 0 in l i g r o i n e

gave c is9c i s - 1 $ 29 3 g 4 - t e t r a p h e n y I b u t a d i e n e e An e l e c t r o n t r a n s f e r mechanism was proposed to acc o u n t f o r t h i s 0

A ttem pts to d e t e c t an nmr e m is s io n s p e c t r a from th e r e a c t i o n of

t~ b u ty 1 lithium-DPA-TMEDA in c y c lo o c ta n e w ere n o t s u c c e s s f u l e

D e u te r o ly s i s o f th e r e a c t i o n betw een 1 -pheny lp ropyne and a s i x

f o ld ex ce ss of n - b u t y l l i t h i u m , i n hexane gave a m ix tu re o f t r i - and

t e t r a d e u t e r a t e d 3 -p h e n y Ip ro p y n e 0 When TMEDA was p r e s e n t i n th e r e a c

t i o n m ix tu re , l e s s d e u te r iu m was found to be in c o rp o r a te d in t o th e

p ro d u c t . Two e x p la n a t io n s f o r . t h i s were p ro p o sed .

INTRODUCTION

In r e c e n t y e a r s o rg a n o l i th iu m compounds have r e c e iv e d a g r e a t

d e a l o f a t t e n t i o n , to a l a r g e e x t e n t b eca u se such compounds i n i t i a t e

s t e r e o s p e c i f i c a n io n ic p o ly m e r iz a t io n s (O v e rb e rg e r , M ulvaney, and

S c h i l l e r 1965)O The b e s t known e x a m p le .o f t h i s i s th e p o ly m e r iz a t io n

o f i s o p re n e to p o ly ( c i s - l , 4 - i s o p r e n e ) ; n a t u r a l ru b b e r ( S ta v e ly e t a l«

1956; H sieh and Tobolsky 1957)«

A s tu d y of th e r e a c t i o n s o f d i s u b s t i t u t e d a c e ty le n e s w i th

o rg a n o l i th iu m compounds was u n d e r ta k e n in th e s e l a b o r a t o r i e s ( S 0 Card™

lund 1963, Z0 Gardlund 1964, F o lk 1964, C arr 19 6 6 )0 T h is d i s s e r t a t i o n

d e a l s w i th a. c o n t i n u a t i o n o f t h a t s tu d y ,

• R e a c t io n s o f O rg a n o li th iu m Compounds w i th A c e ty le n e s

Z, G ardlund (1964) as w e l l as E isc h and Kaska (1962) independ

e n t l y observed t h a t p h e n y l l i t h iu m and d ip h e n y la c e ty le n e (DPA) r e a c t i n

e t h e r to g iv e a f t e r c a r b o n a t io n an 11% y i e l d o f t r i p h e n y l a c r y l i c a c i d .

However, th e r e a c t i o n o f p r im ary a l k y l l i t h i u m compounds w i th DPA in

e t h e r gave v e ry l a r g e l y a d i l i t h i a t e d in t e r m e d i a t e ( l a , b ) which a ro s e

from o y m e ta la t io n as w e l l as a d d i t i o n to th e t r i p l e bond (Mulvaney e_t

a l , 1966), The a s s ig n m e n t of t r a n s s te r e o c h e m is t ry -w a s made on th e

b a s i s of s p e c t r o s c o p i c and chem ica l d a t a . F u r th e r work by Mulvaney

1

2

\ i

1 a , b

l a , R = n-Bu

1b, R = C 2 H 5

and Carr (1 9 6 8 ) on the r e a c t i o n o f the brom ides ,2 and 3 w i th n - b u t y l -

l i t h iu m dem onstrated t h a t the r e a c t i o n o f n - b u t y l l i t h i u m w ith DPA to

g iv e la p ro ceed s by i r r e v e r s i b l e a d d i t io n o f the o r g a n o l i th iu m compound

to DPA, f o l lo w e d by _ o -m eta la t ion , and t h a t the s t e r e o c h e m is tr y o f the

p rod u cts does n o t r e f l e c t the i n i t i a l mode o f a d d i t io n .

n-Bu\ ; = C ( c 6H5)B r

^ 6 ^ 5

32/V>

I n v e s t i g a t i o n o f the r e a c t io n o f a t e r t i a r y o r g a n o l i th iu m com

pound, _ t -b u ty l l i t h iu m , w i th DPA gave somewhat more c o m p lic a te d r e s u l t s .

S in c e _ t -b u ty l l i th iu m r e a c t s r a p id ly w i t h e th e r a t tem peratu res above

-5 0 ° ( B a r t l e t t , Friedman, and S t i l e s 1 9 5 3 ) , a hydrocarbon s o lv e n t

( l i g r o in e - p e n t a n e ) was em ployed . The p rod u cts en cou n tered a f t e r carbon-

a t io n or h y d r o l y s i s a r o s e from both the m o n o l i t h ia t e d in te r m e d ia te (4 )

and the d i l i t h i a t e d in te r m e d ia te ( 5 ) . The a ss ign m en t o f tra n s

s t e r e o c h e m is tr y was based on product d i s t r i b u t i o n and su b seq u en t r e a c

t io n s o f the p rod u cts (Carr 1 9 6 6 ) .

At a h ig h e r tem perature ( 7 0 ° ) the r e a c t i o n o f _ t -b u ty l l i t h iu m

and DPA f o l l o w s a d i f f e r e n t cou rse ( S . Gardlund 1963, Z. Gardlund 1 9 6 4 ) .

The i s o l a t e d p rod u cts on h y d r o ly s i s were c i s , c i s - l , 2 , 3 , 4 - t e t r a p h e n y l b u -

ta d ie n e ( 6 ) , t r a n s - s t i l b e n e ( 7 ) , and i s o b u t y le n e ( 8 ) . From the n a tu re

o f the p rod u cts and the f a c t t h a t a l o n g - l i v e d e s r s i g n a l was observed

i t was apparent t h a t e l e c t r o n t r a n s f e r from J t -b u ty l l i t h iu m to the a l -

kyne was o c c u r r in g .

At th a t time i t was learned from B a r t l e t t (1 9 6 3 ) th a t Tauber

(1 9 5 8 ) had a l s o examined the _ t-bu ty llith iu m -D P A r e a c t i o n in e th e r a t

- 3 0 ° . A f t e r c a r b o n a t io n he ob ta in ed an 11% y i e l d o f 4 , 4 -d im e th y 1 - 2 ,3 -

d ip h e n y l - 2 - p e n t e n o ic a c id , an a d d i t io n p ro d u ct , but the p r in c ip a l

product (43%) was shown to be the l a c t o l 9 , which must have a r i s e n from

e l e c t r o n t r a n s f e r from _ t -b u ty l l i th iu m to DPA.

A com parison o f the r e s u l t s o b ta in ed by Tauber (1958 ) w ith

th o se o f S, Gardlund (1 9 6 3 ) and Z. Gardlund (1964 ) has led to the r e

a c t i o n scheme g iv e n on page 4 .

t-BuLi DPA C,H,C=CC.H„ t-Bub b I b o

t-BuLi

Li

C H

CH

V

3 \^ C = C H g

8rv

c6h 5c = c c 6h 5

Li Li

CO.

V

h 2 o

H x / C 6 H ,

/ C==CXMc 6 Hs H

7rv

LiH20

Li

V

c6

6

zOLio = c

>-<Li

c 6 h 5 c , h 5

oII

t-BuCOLi

OLi OLi I „

c - c NC* Hs

O Z h 2o

\6 * ' 5 Cr.H6 ' ' 5

0rv

In r e la t e d work, K andil and D essy (1966 ) have d e s c r ib e d two ap

p aren t in tr a m o le c u la r a d d i t io n s o f o r g a n o l i th iu m r e a g e n ts to t r i p l e

bonds as shown b e low . In th e se s y s te m s , h a lo g e n -m e ta l exchange would

1. n-BuLi

2 . l-l2 0

c ,h 5CI I IC I

1. n-BuLi

2. H00->

produce a c a r b o n - l i th iu m bond in d i r e c t p r o x im ity to the t r i p l e bond.

However, the p o s s i b i l i t y o f a r a d i c a l pathway was n o t exc lu d ed ( s e e

b e lo w ) .

Ward (1967) r ep o r ted th a t tre a tm e n t o f 6 -b r o m o -1 -p h e n y l-1-

hexyne (1 0 ) w ith e x c e s s n - b u t y l l i t h i u m , fo l lo w e d by h y d r o l y s i s , gave

b e n z y l id e n e c y c lo p e n ta n e (1 1 ) in 60% y i e l d , and p rod u cts o f c o u p l in g

( 1 2 ) , r e d u c t io n ( 1 3 ) , and e l i m in a t io n (1 4 ) in s m a l le r am ounts. On the

b a s i s o f d e u t e r o l y s i s ex p er im en ts and the o b s e r v a t io n o f " c h e m ic a lly

induced dynamic n u c le a r p o l a r i z a t i o n ’1 in a c l o s e l y r e l a t e d sy stem , i t

i s l i k e l y t h a t t h i s r e a c t i o n p roceed s by a r a d i c a l pathway.

, x 1. n -B uL i HCfiH5C = C (C l- i2) Br ------- :-------------------->

2 - H , 0 c f n ,

10 11O' rv

c6h5c=c(ch?)ch3 c6 h5c=c(ch2)ch312 13

rv

... c 6 h 5c = c ( c h 2)2c h = c h 2 14

The r e a c t i o n o f 1-phenylpropyne (1 5 ) w i th a l k y l l i t h i u m s has

been s tu d ie d to some e x t e n t by F o lk ( 1 9 6 4 ) . I t was found t h a t , u n l ik e

DPA, n - b u t y l l i t h i u m or _ t -b u ty l l i t h iu m does n o t add a c r o s s the t r i p l e

bond, bu t in s te a d produces p o l y l i t h i a t e d in te r m e d ia t e s w h ich , on t e r

m in a t io n by h y d r o l y s i s or d e u t e r o l y s i s , g iv e rearranged p rod u ct , 3-

phenylpropyne ( 1 6 ) .

7

In r e la t e d work, W est, Carney, and Mineo (1 9 6 5 ) have rep orted

th a t trea tm en t o f propyne w ith a s i x - f o l d e x c e s s o f n - b u t y l l i t h i u m in

hexane produces a t e t r a l i t h i a t e d in te r m e d ia te (C^Li^) which r e a c t s w ith

t r i m e t h y l c h lo r o s i l a n e to g iv e the a l l e n e ( 1 7 ) .

(Me3Si)2C = C = C ( S i M e 3)

17n j

R e a c t io n s o f O rg a n o m e ta ll ic Compounds w i th A c e t y le n e s -E x c lu d in g O rgan o lith iu m Compounds

There are many exam ples in the l i t e r a t u r e o f a d d i t io n s o f organo-

aluminum compounds a c r o s s carb on -carb on t r i p l e bonds ( E is c h 1 9 6 7 ) . Two

exam ples which are r e l a t e d to our work are the r e a c t i o n o f t r ip h e n y l -

aluminum w ith DPA ( E is c h and Kaska 1962) and the r e a c t i o n o f a lk y la lu m

inum h y d r id e s w i th 1-phenylpropyne (E is c h and Kaska 1 9 6 3 ) .

C f H s / o H s C = ( ^D P A a i (c 6m51 >

2 0 0 '^ 6

-N-

Grignard r e a g e n ts o r d i n a r i l y do n o t add to a c e t y l e n e s (Kharasch

and Reinmuth 1954); how ever, K andil and D cssy (1966 ) have d e s c r ib e d the

i s o l a t i o n o f b e n z y l id e n e f lu o r e n e (1 8 ) from the r e a c t io n o f 2 - i o d o - 2 ’ -

p h e n y le th y n y lb ip h e n y l ( 1 9 ) w i th magnesium in t e t r a h y d r o fu r a n .

1 Mg

2. H20->

C

18rv

T s u ts u i (1962 ) has r ep o r ted t h a t phenyImagnesium bromide p o ly

m er ize s DPA in t e t r a h y d r o fu r a n -x y le n e to the c y c l i c o l ig o m e r s h ex a -

phenylbenzene (2 0 ) and o c t a p h e n y I c y c lo o c t a t e t r a e n e ( 2 1 ) .

9

DPA C6 H 5 Mg Br

V

Ph Ph Ph

Ph Ph Ph»V%

Ph

Ph

Ph

Ph Ph 2120

There are s e v e r a l exam ples in the l i t e r a t u r e o f a d d i t io n s o f

o th e r o r g a n o a lk a l i m eta l compounds to DPA. Iwai and Ide (1965 ) have

r e p o r ted t h a t dim syIsodium adds to DPA a t 25° to y i e l d on h y d r o l y s i s an

88% c i s , 12% tra n s m ix tu re o f the co r re sp o n d in g s t i l b e n e ( 2 2 ) . When

the r e a c t io n tem perature was in c r e a s e d to 40° the o n ly p rod u ct o b ta in ed

was 2 , 3 - d ip h e n y Ib u ta d ie n e ( 2 3 ) . A ls o , a -c u m y lp o ta ss iu m r e a c t s w i th DPA

to y i e l d on c a r b o n a t io n the u n sa tu r a te d a c id 24 o f undeterm ined s t e r e o

DPA CM3SOCS-l2~ N a +

CH,SOCH

22 23

c h e m is tr y ( Z i e g l e r and D i s l i c h 1 9 5 7 ) .

10

D PA +

C H 3i

C6 H5 C - Na IC H ,

COcc/ ^ c h 3

-> C H 3/C = C (C 6M5) C 0 2i-

C 6 H 5

24rw

Use o f T e r t ia r y Amines w ith O rg a n o m e ta ll ic Compounds

The e f f e c t o f t e r t i a r y amines on the r e a c t i v i t y o f o r g a n o l i t h -

ium compounds was noted by J o n e s , Zinn, and Hauser ( 1 9 6 3 ) . They ob

served t h a t the r e a c t i o n o f n - b u t y l l i t h i u m w ith the b e n z y l i c t e r t i a r y

amines 25 and 27 in e th e r gave a f t e r d e u t e r o l y s i s e x c l u s i v e l y p roducts

(26 and 28) a r i s i n g from o - m e t a la t io n . S in c e benzene i s r in g -m e ta la te d

c 6 h 5 c h 2n (c h 3)

25

1. n-BuLi

2. D o O>

^ r H 2 N ( C H 3l

CM/ C M ,

27

1. n-BuLi

2. D oO

CH.C H 2D

'c m 2!< c m 31

28

11

and to lu e n e s id e - c h a i n m eta la te d to o n ly sm a l l e x t e n t s on pro longed r e -

f lu x i n g w ith e t h e r a l n - b u t y l l i t h i u m (Young 1937; Gilman, P a c e v i t z , and

Baine 1940; Gilman and Gaj 1963 ) , the m e t a la t io n s d e s c r ib e d were e v i

d e n t ly g r e a t l y f a c i l i t a t e d by the p r e se n c e o f the t e r t i a r y amine

grou p s . In a l l c a s e s , the s i t e o f m e t a la t io n was such t h a t the amino

n i t r o g e n cou ld c o o r d in a te w ith the l i t h iu m o f the m e ta la te d in te r m e d i

a t e through a f i v e - or six-membered r i n g .

In a su b seq u en t p u b l i c a t i o n , Booth and R o c k e t t (1 9 6 7 ) have

shown th a t d im e th y la m in o m eth y lferro cen e and 2 - f e r r o c e n y l p y r id in e under

go s p e c i f i c 2 - l i t h i a t i o n by n - b u t y l l i t h i u m in e th e r -h e x a n e to g iv e the

c o rresp o n d in g in te r m e d ia t e s 29 and 30 . A gain , c o o r d in a t io n between the

n i t r o g e n and the l i t h iu m to form a five-m em bered r in g was proposed to

e x p la in the r e s u l t s .

—C H o

2 9

Li ^

30

I t has been dem onstrated (E berhardt and B u tte 1964, Eberhardt

and D avis 1965) th a t n - b u t y l l i t h i u m , c o o r d in a te d w i th 1 , 4 - d i a z a b i c y c l o -

[ 2 , 2 , 2 ) oc tan e (3 1 ) or N ,N ,N ’ ,N ’ - te t r a m e th y le th y le n e d ia m in e (TMEDA, 3 2 ) ,

r a p id ly t r a n s m e ta la te s to the b e n z y l i c p o s i t i o n o f t o lu e n e , to the

12

arom atic n u c le u s o f b en zen e , and a n a lo g o u s ly to o th e r a ro m a tic hydro

carbons . The in c r e a s e d r e a c t i v i t y o f • the n - b u t y l l i t h i u m was a t t r i b u t e d

(CH3) / V < c h 3),

31 32/'"■u

to the fo rm a t io n o f a c o o r d in a t io n complex (3 3 ) betw een the o r g a n o l i th -

ium compound and the b i d e n t a t e l ig a n d .

R Li

CHo CH

■

C H 3 c h 3

33rw

In r e l a t e d work, West and Jones (1968 ) have r e p o r te d t h a t t o l u

ene undergoes p o l y l i t h i a t i o n w i th e x c e s s n - b u t y l l i t h i u m in the p r e s e n c e

o f TMEDA. D e r i v a t i z a t i o n o f the r e a c t i o n m ixtu re w i th t r im e th y 1ch 1o r o -

s i lan e y i e l d e d CX, C X . ,£ * * tr i s ( t r im e th y ls i ly l ) to lu e n e as th e major p rod u ct

a lo n g w i t h mono- and b i s ( t r i m e t h y l s i l y l ) t o l u e n e s .

#

13

CM

-i- n-BuLi —TWiEDAM e, Si Cl

-!>

Ch!(SiMe3)

S i M e ,

C H 2SilVi83 CH gSifV ieg

SifVIe

46% 23% 11%

7%

CM

2%

CM

S M e ,

i%

I t i s i n t e r e s t i n g to n o te t h a t s t a b l e com plexes o f d ia lk y lm a g -

nesiurns w i t h TMEDA have been r e p o r te d (Zakharkin 1964; Coates and Hes-

lop 1 9 6 6 ) . In a d d i t i o n , w i th N ,N ,N ' ,N ’ - t e t r a e t h y le t h y le n e d ia m in e

(TEEDA) and an e th e r s o l u t i o n o f £ -f lu orop h en yIm agn esiu m brom ide, the

s t a b l e Grignard adduct C^H^FMgBr-TEEDA was o b ta in ed ( Evans and Khan

1 9 6 7 ) . T h is complex was s o l u b l e in arom atic s o l v e n t s , was monomeric in

ben zen e , and the s o l u t i o n s showed no tendency during s e v e r a l days to

d i s p r o p o r t io n a t e to g iv e the s p a r in g ly s o lu b le MgBr^-TEEDA ad d u ct .

RESULTS AND DISCUSSION

R e a c t io n s o f O rgan o lith ium Compounds and A c e ty le n e s in the Absence o f Added Amine

n - B u t y l l i t h iu m and DPA. S. Cardlund (1 9 6 3 ) and Z. Cardlund

(1964 ) found e v id e n c e f o r the f o l l o w i n g r e a c t io n betw een n - b u t y l l i t h i u m

and DPA in e t h e r .

D P A -i- n -B u LiD , 0

C O

n-Bu

34

6 r “5

r̂>

n-Bu yCg Hg-> " C = C

y XC 0 2H

\\ // CO.U!

,n-Bu x -

IIO

35r̂J 36rxv

The s t e r e o c h e m is t r y o f 34 was dem onstrated by i t s p h oto isom er i'

z a t i o n , i s o l a t i o n o f the new g e o m e t r ic a l isom er and com parison o f the

u l t r a v i o l e t and nmr s p e c t r a o f the two isom ers (S . Cardlund 196 3 ) .

E vidence f o r the p o s i t i o n o f r in g m e t a la t io n , how ever, was n o t

c o m p le te ly u n e q u iv o c a l and was based l a r g e l y upon the f a c t t h a t indone

14

15

36 was i s o l a t e d . In t h i s work the s t r u c t u r e s o f 34 and 35 were proven

in the f o l l o w i n g way. The d i c a r b o x y l i c a c id 35 was co n v er ted to a

monomeric anhydride 37 by tre a tm e n t w i th t h io n y l c h l o r i d e , and t h i s

an h yd rid e , in tu rn , was h yd ro lyzed under m ild c o n d i t io n s back to 35 .

SOCI

Although t h i s o b s e r v a t io n i s in accord w ith s t r u c t u r e 35 , as

w e l l as the indone 36 , i t does n o t r ig o r o u s l y r u le ou t a s t r u c t u r e such

as 38 f o r the d i c a r b o x y l i c a c i d . E a r l i e r a t te m p ts to o x i d a t i v e l y

16

n-Bu ,C6H0 s 0 4

N a l 0 4 >

\ /\

5

34

D

71%

(Ox)

V

o = c \OH

The b en za ld eh y d e-(X -d c o n ta in e d 0 .9 7 D /m o le c u le , and the deu

ter ium was shown to be a ld e h y d ic by nmr s p e c tr o s c o p y and o x id a t io n w i th

b a s i c p o tass iu m permanganate to d e u te r iu m -fr e e b e n z o ic a c i d . The deu

ter ium in the valerphenone-jD-d ( 0 .9 2 D /m o le c u le ) was shown to be in the

benzene r in g or th o to the ca rb o n y l group by the in t e g r a t e d nmr spectrum

which in d ic a t e d the p r e se n c e o f o n ly one lo w - f i e I d o r th o hydrogen c e n

tered a t T 1 .9 6 . By a n a lo g y , t h e r e f o r e , the s t r u c t u r e o f the d ic a r b o x -

y l i c a c id must be 35 .

c o n ta in 0 .2 8 D /m o le c u le , and c o n t r o l exp er im en ts dem onstrated th a t t h i s

deuterium was n o t in c o rp o ra te d du r in g the w ork-up . These r e s u l t s , in

c o n ju n c t io n w ith the o b s e r v a t io n s o f MuIvaney and Carr (1 9 6 8 ) ( 1 . the

a d d i t io n o f n - b u t y l l i t h i u m to DPA occu rs f i r s t , fo l lo w e d by m e t a la t io n ,

2. the a d d i t io n o f n - b u t y l l i t h i u m to the a c e t y l e n e bond i s i r r e v e r s i b l e ,

and 3 . the tra n s s t e r e o c h e m is tr y o f the p ro d u cts does n o t r e f l e c t the

i n i t i a l mode o f a d d i t io n ) have led to the f o l l o w i n g r e a c t i o n scheme:

The recovered DPA from the n - b u t y l l i t h i u m r e a c t i o n was found to

17

t , -B u ty l l i th iu m and DPA. These r e a c t io n s were c a r r ie d out in

l i g r o i n e r a th e r than e t h e r , b ecau se e t h e r s are r e a d i l y c le a v e d by t e r

t i a r y o r g a n o l i th iu m compounds. When t - b u t y l l i t h i u m and DPA were a l

lowed to r e a c t a t 40° and the r e a c t i o n m ix tu re term in ated by c a r b o n a t io n

or h y d r o l y s i s , a number o f p rod u cts were i d e n t i f i e d which were s i m i l a r

to the p rod u cts o b ta in ed w ith n - b u t y l l i t h i u m and DPA. However, when

the same r e a c t io n was c a r r ie d ou t a t 7 0 ° , fo l lo w e d by h y d r o l y s i s th e r e

was i s o l a t e d c i s , c i s - l , 2 , 3 , 4 - te tr a p h e n y I b u ta d ie n e ( £ ) , t r a n s - s t i l b e n e

O ) , and i s o b u t y le n e ( 8 ) ( s e e I n t r o d u c t i o n ) .

There was a p o s s i b i l i t y th a t the t - b u t y l l i t h i u m m ight have d e

composed a t the tem perature employed to g iv e i s o b u t y le n e and l i t h iu m

h y d r id e . One cou ld then argue t h a t the t e t r a p h e n y lb u ta d ie n e a r o s e by

18the a d d i t io n o f l i t h iu m h y d r id e to DPA fo l lo w e d by the a d d i t io n o f a

second mole o f DPA. However, trea tm en t o f DPA w ith l i t h iu m h y d r id e

under the r e a c t i o n c o n d i t i o n s r e s u l t e d o n ly in the r e c o v e r y o f un

r e a c te d a lk yn e (Z. Gardlund 1 9 6 4 ) ,

A d d it io n a l e v id e n c e f o r the e l e c t r o n t r a n s f e r mechanism was ob

ta in e d when the _ t-bu ty llith iu m -D P A r e a c t i o n m ixtu re was t r e a te d w ith

deuterium o x id e . The i s o l a t e d c i s , c i s - l , 2 , 3 ,4 - t e t r a p h e n y lb u t a d ie n e

co n ta in ed 1 .9 4 D /m o le c u le . T his o b s e r v a t io n a l s o r u l e s ou t the p o s s i

b i l i t y t h a t the r e a c t i o n b e g in s by h y d r id e t r a n s f e r from t - b u t y l l i t h i u m

to DPA.

c m , c mi 3 \ l

C M , — C - 7 - L i \ - - - - - - - > C M ; — C3 | V ^ \ ll

C M 2

C g H 5 c = = C C 6 M 5 p ; L i

W ^ c = c c 6 h 5H 5

n - B u t y l l i t h iu m and 1 -P h en y lp rop yn e . No a d d i t io n or e l e c t r o n

t r a n s f e r was observed in the r e a c t i o n o f e i t h e r n - b u t y l l i t h i u m in e th e r

or hexane , or t . - b u t y l l i t h iu m in pentane w i th 1 -p h en y lp rop yn e , but

r a th e r the a lk yn e was iso m e r iz e d to 3 -pheny lpropyne in 50-75% y i e l d

(Mulvaney, F o lk , and Newton 1 9 6 7 ) .

19

1. RLi inC g M g C s s C C h ^ —7— > C 6 H 5C H 2C = C h 3

EtgO or R h2. H20

R = n-Bu or t-Bu

When 1 .0 mol-e o f 1-phenylpropyne was t r e a t e d w i t h 6 .0 m oles o f

n - b u t y l l i t h i u m in hexane f o r 16 hr under r e f l u x f o l lo w e d by a d d i t io n o f

deuterium o x id e to the r e a c t io n m ix tu r e , d e u te r a te d 3 -pheny lpropyne was

o b ta in e d . The nmr spectrum o f the p rod u ct showed no a l i p h a t i c p r o to n s ,

and deuterium a n a l y s i s r e v e a le d the p r e se n c e o f 3 .2 2 D /m o le c u le . The

product w as, t h e r e f o r e , e s s e n t i a l l y 39 probab ly admixed w ith a sm a ll

amount o f 40 which must in turn have a r i s e n from the p o l y l i t h i a t e d

CcI-IcC D 2C = C D c 6 m4d c d 2c = c d

36 40

in te r m e d ia t e s 41 and 4 2 ./-sv rv

3Cg H5C3Li3 C6 H4LiC3Li

41 42

No deuterium was found to be in c o r p o r a te d i n t o e i t h e r s t a r t i n g

m a te r ia l or p roduct under the d e u t e r o l y s i s work-up c o n d i t i o n s .

20

R e a c t io n s o f O rgan o lith ium Compounds and A c e ty le n e s in the P r e sen ce o f N ,N ,N * ,N * -T e tr a m e th y le th y le n e d ia m in e (TMEDA)

I t has r e c e n t l y been r e p o r te d t h a t TMEDA g r e a t l y enhances the

r e a c t i v i t y o f o r g a n o l i th iu m compounds. For exam ple, benzene i s quan

t i t a t i v e l y m e ta la te d by the n-butyHithium-TMEDA complex and the r e

s u l t i n g phenyllithium-TMEDA complex can i n i t i a t e the p o ly m e r iz a t io n o f

e t h y le n e (E berhardt and B u tte 1 9 6 4 ) . A lthough the d e t a i l s o f the TMEDA

a c t i v a t i n g p r o c e s s are n o t known, the r e a so n a b le assum p tion has o f t e n

been made th a t the b i d e n t a t e amine d e p o ly m e r iz e s the a s s o c i a t e d organo-

l i t h iu m compound and le a d s to the fo rm a t io n o f a h i g h l y r e a c t i v e c o o r

d i n a t io n complex (3 3 ) in which the i n d u c t iv e e f f e c t o f the e l e c t r o n s on

the n i t r o g e n l ig a n d s le a d s to an in c r e a s e o f the n u c l e o p h i l i c i t y o f the

R group.

I t was a n t i c i p a t e d t h a t TMEDA would prove u s e f u l in the a c e t y

le n e work, and t h i s indeed was the c a s e . R e a c t io n s occurred much more

r a p id ly and in some c a s e s more c l e a n l y .

P h e n y l l i th iu m and DP A. P h e n y l l i t h iu m in e th e r r e a c t s s lo w ly

(24 h r ) w i th DPA to g iv e on c a r b o n a t io n an 11% y i e l d o f t r i p h e n y l a c r y 1i c

a c id (E isc h and Kaska 1962, Z, Gardlund 1 9 6 4 ) .

c o 2 C'5H 5 / C c = c

c 6 h 5 c o 2 h

A m ix tu re o f 1 .0 mole o f DPA and 2 .5 m oles o f a 1:1 p h e n y l

l i thium- TMEDA complex in hexane was h e a ted under r e f l u x f o r 6 hr and

21

gave on tre a tm e n t w i th d euterium o x id e a 63% y i e l d o f d e u te r a te d t r i

phenyl e t h y le n e c o n t a in in g 1 .6 2 D /m o le c u le .

The p o s i t i o n o f the r in g - m e t a l a t i o n was determ ined by o x id a t io n

o f the product w i th b a s i c p o ta ss iu m permanganate to y i e l d benzophenone-

o-d c o n t a in in g 0 .8 0 D /m o lecu le and b e n z o ic a c id c o n t a in in g 0 .0 5 7 D/m ole

c u l e . The deuterium atom in the benzophenone was shown to be in the

benzene r in g o r th o to the ca rb o n y l group by the in t e g r a t e d nmr spectrum

which in d ic a t e d the p r e s e n c e o f o n ly 3 .2 l o w - f i e I d or th o hydrogens c e n

tered a t T 2 . 3 . The s i g n i f i c a n c e o f the sm a ll amount o f deuterium in

the b e n z o ic a c id w i l l be d i s c u s s e d in a l a t e r s e c t i o n .

I t i s s e en t h a t p h e n y l l i t h iu m in e th e r s lo w ly produces the

m o n o l i th ia te d in te r m e d ia te 43 w hereas the same r e a g e n t in the p r e sen ce

o f TMEDA f a i r l y r a p i d ly produces the d i l i t h i a t e d in te r m e d ia te 44 w ith

m e t a la t io n o c c u r r in g in the o r th o p o s i t i o n o f the benzene r in g to the

v i n y l i c l i t h iu m ,

p 6 ^ 5 M5

c=c / \ c6l-l5 L i

43/■'V

n - B u t y l l i t h iu m and DPA. Treatm ent o f 1 .0 mole o f DPA and 2 .5

m oles o f n - b u t y l l i t h i u m in hexane gave on d e u t e r o l y s i s a 69% y i e l d o f

t r a n s - c o n - b u t y l s t i l b e n e (3 4 ) c o n t a in in g 1 .9 1 D /m o le c u le . The g lp c

c=c

44/'XV

22

r e t e n t i o n time u s in g a 10 V 207o'GE-SE-30 column and nmr spectrum o f the

product were i d e n t i c a l w i th th a t o f 34 prepared in e t h e r 0

In a d d i t io n , o x i d a t i v e c le a v a g e o f 34 prepared in hexane w i t h

osmium t e t r o x id e and sodium m e ta p e r io d a te gave 74% benzaldehyde-oC rd,

( 0 o91 D /m o le c u le ) and 52% v a le r o p h e n o n e -o -d ( 1 ,0 3 D /m o le c u le ) 0 The c a r

bony l compounds gave i d e n t i c a l nmr s p e c t r a ' a s th o se o b ta in ed from the

o x id a t io n o f 34 prepared in e t h e r 6

■ O x id a t io n o f the b e n z a ld e h y d e -c x -d w i th b a s i c p o ta ss iu m perman

ganate gave b e n z o ic a c id c o n t a in in g 0 ,0 1 9 D /m olecu le*

S in ce n - b u t y l l i t h iu m , and DPA do n o t r e a c t in pen tan e over a

p er io d o f many hours (Z 0 Gardlund 1964) th e above r e s u l t s show t h a t the

p r e sen ce o f TMEDA n o t o n ly i n c r e a s e s the r e a c t i v i t y o f n - b u t y l l i t h i u m .

in m e t a la t io n r e a c t io n s ( s e e I n t r o d u c t io n ) b u t a l s o in i t s a d d i t io n r e

a c t i o n to DPA0 Note a g a in the p r e s e n c e o f a sm a ll amount o f deuterium

in the b e n z o ic a c id o b ta in ed from c le a v a g e o f the t r a n s - Q i~ n ~ b u ty l s t i f ~

bene ( 3 4 ) 0

_t-Butyl l i t h iu m and DPA0 P roducts s im i la r to th o s e in the n~

b u t y l l i t h iu m c a se have been re p o r te d by Z0 Gardlund (1 9 6 4 ) and Carr

(1966 ) f o r the r e a c t i o n o f t y b u t y l l i t h i u m w ith DPA in l i g r o i n e ( 4 0 ° ,

22 h r ) .

A f te r c a r b o n a t io n , th e r e was o b ta in ed 2 - pheny1 - 3 - ( ^ c a r b o x y -

p h e n y l ) - 4 ,4 - d im e t h y l - 2 - p e n t e n o i c a c id ( 4 6 ) , 4 , 4 - d im e t h y l~ 2 ,3 - d ip h e n y l -

2 - p e n te n o ic a c id ( 4 7 ) , 2 -p h e n y l -3 - j t -b u ty l in d o n e ( 4 8 ) , and reco v e r e d

DPA. When the r e a c t i o n was term in ated by h y d r o l y s i s g lp c r e v e a le d the

p r e se n c e o f 80% u n rea c ted DPA and a m ix tu re o f the two p o s s i b l e

23

g e o m e t r ic a l isom ers o f o c - t - b u t y l s t i l b e n e . In agreem ent w i th the

h y d r o l y s i s and c a r b o n a t io n r e s u l t s , d e u t e r o l y s i s o f the r e a c t i o n m ix

tu re produced d e u te r a te d c x - t - b u t y l s t i l b e n e (4 5 ) c o n t a in in g 1 .5 6 D/mo1-

e c u le (Z . Gardlund 1 9 6 4 ) .

DPA "I* t-BuLi

C O

0 , 0

or M20

L— >

t-Bu

46

->

t-Buxc=c(c6 h 5) d

( h )

t-Bu\

C — c(c6 H5)C Or

47

+

48

t-Bu

The d i c a r b o x y l i c a c id 46 was c o n v e r te d to i t s seven-membered

r in g anhydride 49 which in turn cou ld be h yd ro lyzed w i th d i l u t e sodium

h yd rox id e to the same d i c a r b o x y l i c a c id 46 , thus p r o v in g the tran s

24

t-BuSOCI

o49r̂ >

arrangem ent o f the phenyl groups (Carr 1 9 6 6 ) . In order to o b ta in

2 - pheny1 - 3 - 1 ~ b u ty1indone (4 8 ) and the d i c a r b o x y l i c a c id ( 4 6 ) , the

t r a n s -p h e n y l in te r m e d ia te ( 5 ) must have been p r e s e n t in the r e a c t io n

m ixtu re b ecau se i t has been shown th a t c a r b o n a t io n or h y d r o l y s i s o f

5

v i n y l i c l i t h iu m compounds occu rs w i th r e t e n t i o n o f c o n f ig u r a t io n (S e y -

f e r t h and Vaughan 1 9 6 4 ) .

On the b a s i s o f the c o m p o s i t io n o f the i s o l a t e d p r o d u c ts , as

known a t t h a t t im e , Carr (1966 ) made the r e a so n a b le assu m p tion t h a t the

m on ocarb oxy lic a c id 47 and the major component o f the O C -_ t -b u ty ls t i l -

bene m ix tu re both had phenyl groups t r a n s . In the l i g h t o f t h i s work,

t h a t a ss ig n m en t w i l l have to be changed.

25

Carr (1966 ) a l s o found o th e r compounds s i m i l a r to 46 and 47 e x -

c e p t th a t an a d d i t io n a l t - b u t y l group was a t ta c h e d to one o f the ben

zene r in g s in an unknown l o c a t i o n . I t has s u b s e q u e n t ly been found th a t

the d i -J t -b u ty l compounds are the major p ro d u cts in t h i s r e a c t io n (Mul-

vaney and Groen 1 9 6 8 ) .

Treatm ent o f 1 .0 mole o f DPA and 2 ,5 m oles o f TMEDA w ith 2 .5

m oles o f _ t -b u ty l l i th iu m in pentane gave on c a r b o n a t io n 41% c i s - 4 , 4 -

d i m e t h y l - 2 ,3 - d i p h e n y l - 2 - p e n t e n o ic a c id ( 5 0 ) , 6% c i s - Q t - t - b u t y l s t i l b e n e

and a t r a c e o f 2 - p h e n y l -3 - t~ b u t y l in d o n e (^48). The m onocarb oxy lic a c id

(5 0 ) was i d e n t i c a l w i th th a t o b ta in ed by Z. Gardlund (1964 ) and whichrv

t -Bu COM- > = <

^ 6 ^ 5 ^ 6 ^ 5

50r v

was l a t e r a s s ig n e d the t r a n e - s t e r e o c h e m is t r y by Carr ( 1 9 6 6 ) .

The s t e r e o c h e m is tr y o f 50 was u n e q u iv o c a l ly determ ined as f o l

low s . Treatm ent o f 50 w i t h s u l f u r i c a c id r e s u l t e d o n ly in the r e c o v e r y

o f the s t a r t i n g m a t e r i a l . However, 50 cou ld be p h o to iso m e r iz e d to arv

45:55 m ixture o f the c i s - tra n s i so m e r s , the q u a n t i t i e s o f each b e in g

determ ined by the in t e g r a t e d i n t e n s i t i e s o f the d i f f e r e n t t .-b u ty l

groups in the nmr s p e c tr a o f the i s o m e r s . When a m ix tu r e o f the i s o

mers was t r e a t e d w i th s u l f u r i c a c id , th e r e was o b ta in ed 2 - p h e n y l - 3 ~ t -

b u t y l in d o n e . The nmr spectrum r e v e a le d t h a t o n ly the iso m e r iz e d a c id

26

had r e a c te d and, t h e r e f o r e , must have had a ca r b o x y l group and a pheny l

group e l s to one a n o th e r .

50rvh 2s o 4

-> NR

h"0

- B u \ / C 6 H 5

/ c = c \C6 H5 c o 2 h

m 2s o 4t -B u

6* ' 5

48

The s t e r e o s p e c i f i c i t y o f t h i s r e a c t i o n was f u r t h e r dem onstrated

by the f a c t th a t o n ly t r a n s - 2 , 3 - d ip h e n y l - 2 - h e p t e n o ic a c id (5 1 ) formed

the indone 36 when t r e a t e d w i th s u l f u r i c a c id .r>u

n-Bu C 0 9 H

■ >=<^ 6 ^ 5 I lg

H2so4■»> N R

n -B u C 6 l i 5

/C = C\c 6h 5 c o 2m

H g S O ,■>

IIO

n-Bu

^6 ̂ 5

51rv

3 6

27

These r e s u l t s are a l s o in accord w ith the s t e r e o s p e c i f i c r in g

c lo s u r e o f 52 (Jackman and Lown 1 9 6 2 ) .

3 :<52rw

CH,

C O gH

H2S 0 4- >

CH\ c = c

COgH H 2S 0 4

\ -> NRCH

I t i s i n t e r e s t i n g th a t in the c a s e o f 50 , 51 , and 52 , both c i s° z-xj ’ rv 7 ------

and tran s isom ers are con ver ted to t h e i r c o r re sp o n d in g indones by

t h io n y l c h lo r id e (Mulvaney and Carr 1968, Kampmeier and F a n ta z ie r

1 9 6 6 ) , T h e r e fo r e , s u l f u r i c a c id c y c l i z a t i o n s o f c innam ic a c id d e r iv a

t i v e s p r o v id e a v e r y u s e f u l probe f o r s t e r e o c h e m is t r y , w hereas t h io n y l

c h lo r id e c y c l i z a t i o n s do n o t .

D e u t e r o ly s i s o f a r e a c t io n m ix tu re c o n t a in in g 1 .0 mole o f DPA,

2 .5 m oles o f TMEDA, and 2 .5 m oles o f _ t -b u ty l l i t h iu m y i e l d e d 3 compon

e n t s by g lp c a n a l y s i s ; 14% DPA, 74% c i s - C c - t - b u t y l s t i l b e n e , and 12%

t r a n s - Q t - t - b u t y l s t i l b e n e . Each o f the 3 components was i s o l a t e d and

i d e n t i f i e d by com parison o f g lp c r e t e n t i o n t im e s , nmr s p e c t r a , an d /or

m ixture m e l t in g p o in t s w i th a u t h e n t ic sam ples prepared by Carr ( 1 9 6 6 ) .

Deuterium a n a ly s e s o f the p rod u cts r e v e a le d th a t the DPA co n ta in e d 1 .79

28

D /m o le c u le , the c i s - O C - t - b u t y l s t i l b e n e c o n ta in e d 0 .9 9 D /m o le c u le , and

the t r a n s - C c - t - b u t y l s t i l b e n e c o n ta in e d 1 .05 D /m o le c u le .

The s t e r e o c h e m is tr y o f the e x - t - b u t y l s t i l b e n e s was a s s ig n e d on

the b a s i s o f the f o l l o w i n g argum en ts . As was j u s t p o in te d o u t , carbon-

a t io n o f the _t-butyllithium-DPA-TMEDA r e a c t i o n m ix tu re r e s u l t e d in the

i s o l a t i o n o f a 41% y i e l d (p u re) o f the c i s c a r b o x y l i c a c id 50 . The

t ra n s c a r b o x y l i c a c id was s u r e ly p r e s e n t in the r e a c t i o n m ix tu r e , but

the p rod u cts were too h ig h b o i l i n g f o r a g lp c a n a l y s i s . When the same

r e a c t io n m ixtu re was term in ated by d e u t e r o l y s i s , the two O C -t - b u t y l -

s t i l b e n e s were shown by g lp c to be p r e s e n t in the r a t i o o f 6 : 1 . As was

p o in ted out p r e v io u s l y , c a r b o n a t io n and h y d r o l y s i s o f v i n y l i c l i t h iu m

compounds proceed w ith r e t e n t i o n o f c o n f ig u r a t io n ( S e y f e r t h and Vaughan

1964); t h e r e f o r e , the c i s c a r b o x y l i c a c id 50 must have been the major

product o f the c a r b o n a t io n . B ecause 50 was the major c a r b o n a t io n prod

u c t , the major d e u t e r o l y s i s product must a l s o have had jc is - s t e r e o c h e m

i s t r y . Furtherm ore, 50 was d e c a r b o x y la te d w i th q u in o l in e and copper

chrom ite to a q u a n t i t a t i v e y i e l d o f an O C - t - b u t y l s t i l b e n e i d e n t i c a l

w ith the major component o f the d e u t e r o l y s i s p roduct (Carr 1 9 6 6 ) .

CuCr2 0 4 t B u x / H

£ 5 q u in o l in e ^ / ^ — ^ \240° C 6 H 5 C 6

S im i la r d e c a r b o x y la t io n r e a c t i o n s have p r e v io u s l y been shown to

proceed w ith a h ig h d eg ree o f s t e r e o s e l e c t i v i t y (Mulvaney and Carr

29

1968, C u rtin and H arr is 1 9 5 1 ) . The ab sen ce o f p ro d u cts d e r iv e d from

the d i l i t h i a t e d in te r m e d ia te 5 when TMEDA was p r e s e n t in the t - b u t y l -

lithium -DPA r e a c t io n m ix tu re d e s e r v e s comment. P roducts a r i s i n g from

5 were o b ta in ed when TMEDA was n o t u s e d . A ls o , p rod u cts d e r iv e d v ery

l a r g e l y from the d i l i t h i a t e d in te r m e d ia te la were o b ta in ed from the

r e a c t io n o f n - b u t y l l i t h i u m and DPA both w i t h and w i t h o u t TMEDA p r e s e n t .

The absence o f r in g - m e t a l a t i o n in the c a s e o f _ t -b u ty l l i t h iu m -

DPA i s probab ly a s t e r i c e f f e c t . I f t - b u t y l l i t h i u m and TMEDA e x i s t as

a c o o r d in a t io n complex such as 33, t h i s may s im p ly be to o la r g e to

m e t a la te the benzene r i n g .

To determ in e the r a t e a t w hich _ t-bu ty l l i t h iu m r e a c t s w ith DPA

in the p r e sen ce o f TMEDA, a l i q u o t s o f the r e a c t io n m ix tu re were hydro

lyzed a t v a r io u s i n t e r v a l s . A pproxim ate ly 20 m in u tes were r e q u ired to

mix the r e a g e n t s , and the r e s u l t s i n d i c a t e th a t the r e a c t i o n was com

p l e t e im m ed ia te ly a f t e r a l l o f the t - b u t y l l i t h i u m was added. The prod

u c t c o m p o s i t io n was determ ined by g lp c a n a l y s i s o f h y d ro ly zed a l i q u o t s

and remained c o n s ta n t from 20 min a f t e r m ix in g to 24 hr a f t e r m ix in g .

Using a 2 ,5 : 1 molar r a t i o o f Jt-butyllithium-TMEDA to DPA, the hydro

lyzed r e a c t io n m ixtu re c o n s i s t e d o f 20% DPA, 69% c i s - C t - t - b u t y l s t i l -

b ene , and 11% t r a n s - o c - t - b u t y l s t i l b e n e . That t h e s e are th e o n ly prod

u c t s o f the r e a c t io n was a l s o shown by the nmr spectrum o f the a l i q u o t

hyd ro lyzed 24 hr a f t e r a d d i t i o n .

In a s im i la r ex p er im en t, the m olar r a t i o o f t - b u t y l l i t h i u m -

TMEDA to DPA was v a r i e d . A l iq u o t s were h yd ro lyzed 30 min a f t e r the

a d d i t io n o f each mole o f the t-butyllith ium -TM ED A com plex per mole o f

30

DPA and an a lyzed by g l p c . The r e s u l t s i n d i c a t e th a t between 1 and 2

m oles o f the complex per mole o f DPA were needed to o b t a in a maximum

y i e l d o f the J t - b u t y l s t i lb e n e s ( s e e F ig u re 1 ) . T h is was in agreem ent

w ith the d e u t e r o l y s i s o f the r e a c t i o n m ixtu re r e p o r ted p r e v io u s ly in

which the re co v e r e d DPA c o n ta in e d 1 .79 D /m o le c u le .

c i s - Q t - t - b u t y l s t i l b e n e

6 0 “

5 0 “

40-

30- DPA

20t r a n s " o c -t ,~ b u ty ls t i l b e n e

Moles t_ -B u ty ll ith iu m /M ole DPA

F i g . 1 . P l o t o f 7» P roducts v e r s u s Moles o f _t-Butyl l i t h iu m per Mole o f DPA,

In a d d i t io n , a p r e c i p i t a t e was formed in a l l r e a c t i o n s o f

TMEDA, DPA, and J t -b u ty l l i t h iu m . H y d r o ly s i s o f the p r e c i p i t a t e fo l lo w e d

by g lp c a n a l y s i s showed t h a t i t was the d i l i t h i a t e d DPA-TMEDA com plex .

Prolonged tre a tm e n t o f d e u te r a te d c i s - Q C - t - b u t y l s t i l b e n e w ith

osmium t e t r o x i d e and sodium m e ta p e r io d a te gave o n ly r e co v e r e d s t a r t i n g

31

m a t e r ia l . S in ce t r a n s - o t - n - b u t y l s t i l b e n e was o x i d a t i v e l y c le a v e d q u i t e

e a s i l y under t h e s e c o n d i t i o n s , the s t e r i c e f f e c t o f the _ t-bu ty l group

i s ap p a ren t .

U sing b a s i c p o ta ss iu m permanganate the d e u te r a te d c i s -Q C -t-

b u t y l s t i l b e n e was o x id iz e d to p iv a lo p h e n o n e and b e n z o ic a c i d . Because

o n ly a t r a c e o f a c i d i c m a t e r ia l was o b ta in ed when p iv a lo p h en o n e was

s u b je c te d to the o x i d a t i v e c o n d i t i o n s , the b e n z o ic a c id o b ta in ed c o r

resp onds to the f3 - pheny l r in g o f the c i s -OC- t - b u t y I s t i l b e n e . The

b e n z o ic a c id c o n ta in e d 0 .0 4 8 d euterium atom per m o le c u le . This o b s e r

v a t io n w i l l be d i s c u s s e d in th e l a s t s e c t i o n .

H -B u ty l l i t h iu m and 1 -P h en y lp rop yn e . When 1 .0 mole o f 1-p h e n y l -

propyne was t r e a t e d w ith 6 .0 m oles o f a 1:1 n - b u t y 11ithium-TMEDA complex

in hexane f o r 16 hr under r e f l u x , an orange p r e c i p i t a t e formed in the

r e a c t i o n m ix tu r e . T erm ination by d e u t e r o l y s i s produced d e u te r a te d 3-

phenylpropyne c o n t a in in g 2 .5 4 D /m o le c u le .

Two p o s s i b l e e x p la n a t io n s can a c c o u n t f o r the f a c t th a t l e s s

deuterium was in c o r p o r a te d i n t o the 3 -pheny lpropyne when the t e r t i a r y

amine was p r e s e n t . F i r s t , the p r e c i p i t a t e formed in t h i s c a se may i n

d i c a t e t h a t the d i l i t h i a t e d - a m i n e com plex 53 was i n s o l u b l e in the r e -rv

a c t i o n m ixtu re and p r e c i p i t a t e d , e l i m in a t in g f u r th e r m e t a l a t i o n .

C 6 H5C3HLi2 • 2 T6V1EDA

53r v

32

S eco n d ly , c le a v a g e o f the c a r b o n -n it r o g e n bond o f the TMEDA, ana logous

to the c le a v a g e o f e t h e r s (Rembaum, S ia o , and I n d ic t o r 1 9 6 2 ) , by any

t r i - or t e t r a l i t h i a t e d in te r m e d ia te (41 or 42) p r e s e n t in the r e a c t io nz'xy 1

m ixtu re would a l s o lead to l e s s deu ter iu m in c o r p o r a t io n .

CH, CH„ c f ! CH3 C L iC -H -

V i j uLiCLiCLiCg Hs ^ C J ^ | _

7 < Ac h 3 c h 3 c h 3 c h 3

V

Li N (C!-!3) o -I- 53 -i- (CH3)JMCH = CH,

In r e la t e d work, West e_t a_l. (1 9 6 5 ) have observed t h a t propyne

was m eta la te d by a s i x - f o l d e x c e s s o f n - b u t y l l i t h i u m to the t e t r a l i t h

ia t e d in te r m e d ia te C^Li^. T erm ination o f the r e a c t i o n m ix tu re w ith

t r i m e t h y l c h lo r o s i l a n e gave the a l l e n e 17 r a th e r than an a c e t y l e n e such

as we o b s e r v e . As the a u th o rs p o in t o u t , how ever, t h i s i s very l i k e l y

a s t e r i c e f f e c t and, in f a c t , the t r i l i t h i a t e d product from propyne

when t r e a te d w ith t r i m e t h y l c h l o r o s i l a n e gave 54 .

(Me3Si)2C = C = c ( S i M e J 2

17rv

33

M e 3S i C = C C H ( S i M e 3 ) r

54 5

The Nature o f V in y l l i t h iu m Compounds

I t has been shown by C u rtin and Crump (1958 ) and C urtin and

Koehl (1 9 6 0 , 1962) t h a t a r y l v i n y l l i t h i u m compounds undergo g e o m e tr ic a l

i s o m e r iz a t io n much more r e a d i l y than a l k y l v i n y l l i t h i u m compounds, and

t h a t the r a t e s o f i s o m e r iz a t i o n o f a r y l v i n y l l i t h i u m compounds vary

markedly w ith the s o l v e n t , the r a t e d e c r e a s in g in the order tetrahydro-

f u r a n > 3 : 1 e th e r - b e n z e n e > hydrocarbon s o l v e n t s . The a u th o r s s u g g e s t

t h a t the i s o m e r iz a t i o n o f the v i n y l l i t h i u m compounds occu rs by i o n i z a

t io n o f the p a r t i a l l y c o v a le n t c a r b o n - l i th iu m bond fo l lo w e d by c o n v er

s io n to a l i n e a r t r a n s i t i o n s t a t e or in te r m e d ia te (5 5 ) in which the

charge i s h i g h l y d e l o c a l i z e d and t h a t r e c a p tu r e o f the l i t h iu m ion o c

cu rs to g iv e iso m e r iz e d organom eta11i c .

M H

Hunter and Cram (1 9 6 4 ) have s tu d ie d the c o n f ig u r a t io n a l s t a b i l

i t y o f the v i n y l a n io n s o f c i s - and t r a n s - s t i l b e n e in p o ta ss iu m _t-butox

id e and t - b u t y l a lc o h o l-O -d a t 1 4 6 ° . V in y l i s o t o p i c exchange occurred

more r a p i d ly than i s o m e r iz a t i o n f o r e i t h e r isom er . The au th o rs p o in t

ou t t h a t t h i s o b s e r v a t io n may be r a t i o n a l i z e d in two w ays . The v i n y l2

an ion may e x i s t as a b e n t sp h y b r id iz e d s p e c i e s ( 5 6 ) , which i s o m e r iz e s

through a l in e a r t r a n s i t i o n s t a t e or i n t e r m e d ia t e . The o th e r p o s s i b i l -

HV = c f ' ,V^ 6 ^5 ^ 6 ^ 5

5 6

i t y i s t h a t the s t i l b e n y l c a rb a n io n s e x i s t as l i n e a r sp h y b r id iz e d

s p e c i e s which d i f f e r w i th regard to w hether the p o ta ss iu m ion i s c l o s e

to the f a c e o f the a n ion occup ied by the phenyl group, or to the f a c e

occu p ied by the hydrogen .

H \

Ion p a ir from c i s - s t i l b e n e

c1-3\

C = C ' ------ '

Ion p a ir from t r a n s - s t i l b e n e

R u s s e l l (1 9 5 9 ) has g iv e n d i r e c t e v id e n c e f o r the charge d e l o c a l

i z a t i o n o f b e n z y l c a rb a n io n s from a s tu d y o f the n e u t r a l i z a t i o n o f

p o ta ss iu m cumyl w i th v a r io u s d e u te r a te d a c i d s . The r e s u l t s i n d i c a t e

t h a t weak a c i d s , such as deuterium o x id e , r e a c t w i th th e cumyl an ion to

produce o n ly cumene-CX-d. With s tr o n g a c i d s , such as deu ter iu m

35c h l o r i d e , n e u t r a l i z a t i o n in e th e r in v o lv e d some e l e c t r o p h i l i c a t t a c k a t

the O'- and ^ - p o s i t i o n s o f the an ion to y i e l d the c o r re sp o n d in g r in g -

d e n te r a te d cumene.

K + C H 3— C — C H 3

A

VC H 3— c — CM3

CM 3— C D —CM 3DC!

K

->

C H 3— C — CM ii

H D

CHo—-CM—CM

D

S i m i l a r l y , when O t-m e th y ls ty r e n e i s t r e a te d w i t h J t -b u ty l l i th iu m

in the p r e s e n c e o f t r i m e t h y I c h l o r o s i la n e , compound 57 i s o b ta in ed e x

c l u s i v e l y (Bey and Weyenberg 1 9 6 5 ) .

CH

t - B u L i + CFt0 ~ C

36

[VtegSiCI

CH

Bu

Si Me

57rxv

T h is r e s u l t i n d i c a t e s t h a t fo r s t e r i c r e a so n s the c arb an ion 58 r e a c t s

a t the p a r a - p o s i t i o n .

/■V

Li + t - B u CH2— C —CH3 t -B u CHp — C — C Ho

ii 3

58Li

. +

I f the v i n y l l i t h i u m compounds d e s c r ib e d in t h i s work e x i s t in

p a r t or e x c l u s i v e l y in the l i n e a r form, i t should be p o s s i b l e to o b t a in

prod u cts c o n t a in in g d euterium in the benzene r in g .

I t may be r e c a l l e d from the e a r l i e r p a r t o f t h i s d i s c u s s i o n

t h a t the deuterium o x id e term in ated r e a c t i o n p ro d u cts o f p h e n y l l i t h iu m ,

n - b u t y l l i t h i u m or _ t -b u ty l l i th iu m w it h DPA in the p r e s e n c e o f TMEDA gave

the r e s u l t s shown b e low .

37

R

DPA -I- R Li > V = C(C6 H5) Dc6 H4 D i n

59^a , R - C6 H5 b , R= n -B u c , R - t - B u y

( ° x )

c o 2hR

\ c = oC6 H4D ( h)

5 9 a , 0 . 0 5 7 D / m o ! e c u l e , 0 .0 1 9

c , 0 .0 4 8

The p r e se n c e o f a s m a l l , though s i g n i f i c a n t , q u a n t i ty o f deu

ter ium in the b e n z o ic a c id cou ld have a r i s e n from d e u t e r a t io n o f the

l i n e a r form o f the v i n y l l i t h i u m in t e r m e d ia t e . The pheny1lithium -DPA-

TMEDA system was i n v e s t i g a t e d the m ost th o r o u g h ly . P h e n y l l i th iu m was

prepared by the m e t a la t io n o f benzene u s in g n - b u t y l l i t h i u m in TMEDA

(E berhardt and B u tte 1964) to g iv e a r e a c t io n m ixture which c o n s i s t e d

o f a 2 .5 : 1 m olar r a t i o o f phenyllithium-TMEDA to DPA. R e a c t io n s were

run a t 0° and 25 -30° in a h exan e-b en zen e s o l v e n t and were term inated by

the a d d i t io n o f deu ter iu m o x id e or deu ter iu m c h l o r i d e . The r e s u l t i n g

p r e v io u s ly d e s c r ib e d d e u te r a te d t r i p h e n y l e t h y le n e was o x i d a t i v e l y

c le a v e d w ith b a s i c p o ta ss iu m permanganate fo l lo w e d by a n a l y s i s o f the

b e n z o ic a c id f o r d e u ter iu m . I t has p r e v io u s l y been shown t h a t deuterium

would n o t be washed out o f the p rod u ct under the c o n d i t i o n s o f the o x i

d a t io n (J o n es e t a l . 1 9 6 3 ) . In a d d i t i o n , c o n t r o l ex p er im en ts proved

38

th a t t r i p h e n y l e t h y le n e does n o t exchange w i th deuterium c h l o r i d e under

the work-up c o n d i t io n s o f the phenyllithium-DPA-TMEDA r e a c t i o n . Re

s u l t s o f th e se exp er im en ts are shown in T able I .

TABLE I

AROMATIC DEUTERIUM CONTENT OF BENZOIC ACID OBTAINED BY THE OXIDATIVE CLEAVAGE OF TRIPHENYLETHYLENE

Run No. Temp0 T erm inating D /M olecu le o f B en zo ic AcidAgent Mass. S p e c t . F a l l i n g Drop

1 0 DC1 0 .0 9 4 ± 0 .0 0 1 0 .0 7 8

2 am bient DC1 0 .0 7 6 ± 0 .0 0 2 0 .0 5 6

3 am bient DC1 0 .0 7 8 ± 0 ,0 0 1 -

4 0 D2° 0 .0 7 9 ± 0 .002 0 .0 5 7

There was l i t t l e d i f f e r e n c e in the d euterium c o n t e n t o f the

b e n z o ic a c id r e g a r d le s s o f w hether d eu ter iu m o x id e or deuterium c h l o r

id e was u se d . In R u s s e l l ’ s (1959 ) work w it h cum ylpotassium o n ly the

s tr o n g e l e c t r o p h i l e deu ter iu m c h l o r i d e produced r in g d e u te r a te d prod

u c t ; deuterium o x id e did n o t . However, com parison w i t h t h e s e o b se r v a

t io n s i s obscured by the f a c t t h a t TMEDA was p r e s e n t in our system , and

the e x t e n t to which d e u t e r a t io n o f the o r g a n o l i th iu m compounds by 60

occurred was n o t known.

(c h 3) n c h 2c h 2 n d (c h 3)2

60r o

39I t i s known t h a t in the p h e n y l l i t h iu m or n-butyllithium -TM EDA-

DPA system s the d i l i t h i a t e d in te r m e d ia t e s la and 44 are the s p e c i e s

a c t u a l l y un d ergo in g d e u t e r o l y s i s .

l a , R = n - B u

i R = C 6 H 5

In order to examine the d e u t e r o l y s i s o f the m o n o l i t h ia t e d i n

ter m e d ia te 43 , c c -b r o m o tr ip h e n y le th y le n e was prepared and tr e a te d w ith

l i t h iu m m eta l in hexane or e th e r and TMEDA, A f te r tre a tm e n t o f the

C gH 5 </

\ = C

^ 6 ^ 5\

1

'6 1 ‘ 5 1 . LiC rH 5

B rT [VI E D A 2. D 2 0

\ = c /C r H

D

C 0 9 H

c = o^ 6 ^5

(Ox)

40

r e a c t io n m ixture w ith deuterium c h lo r id e fo l lo w e d by o x i d a t i v e c le a v a g e

o f the p ro d u ct , the i s o l a t e d b e n z o ic a c id c o n ta in e d no m easurable deu

ter ium .

These r e s u l t s a g ree w ith th o se o f Carr (1 9 6 6 ) who c a r r ie d out

the same sequence o f r e a c t io n s w i th 2 in e th e r and term in ated the r e -/V

a c t i o n w i th deuterium c h l o r i d e . Carr found no d euterium in the b e n z o ic

a c id ob ta in ed a f t e r o x i d a t i v e c le a v a g e o f the p r o d u c t .

n-Bu

>=^ 6 ^ 5

2zv

The q u e s t io n im m edia te ly a r i s e s as to why deu ter iu m i s found in

some c a s e s and n o t in o t h e r s . The m ost probab le e x p la n a t io n a t the

moment seems to be in the i n t r i g u i n g a lth o u g h v e x in g ten dency o f organo

l i t h iu m compounds, e s p e c i a l l y in the p r e se n c e o f TMEDA, to produce

p o l y l i t h i a t e d s p e c i e s . A number o f such exam ples have been d i s c u s s e d

in t h i s d i s s e r t a t i o n and a few o th e r s have been r e p o r te d in the l i t e r a

t u r e , For c o n v e n ien ce t h e s e are shown b e low .

Th is work T h is work

West e t a l . 1965Li

West and Jones 1968

CHLi,Ic=o

C6H5CL.i2CN

K a iser and Hauser 1966

In a l l o f our r e a c t io n s in which d e u te r a te d b e n z o ic a c id was

o b ta in e d , an e x c e s s o f o r g a n o l i th iu m compound was a lw ays p r e s e n t and

t h i s may have r e s u l t e d in the fo rm a t io n o f a sm a ll amount o f t r i l i t h i -

ated in te r m e d ia t e .

RliC = C-J>

Another p o s s i b i l i t y th a t can n ot be ru led ou t i s th a t the d i -

l i t h i a t e d in te r m e d ia te e x i s t s to a g r e a t e r e x t e n t in a l i n e a r c o n f i g

u r a t io n than does the m o n o l i t h ia t e d s p e c i e s , b ecau se o f e l e c t r o s t a t i c

r e p u l s io n o f the nearby l i t h iu m atoms or b eca u se o f a s t e r i c e f f e c t due

to the s o l v a t i n g m o le c u le s o f TMEDA,

42

C=c = MLi

C h em ica lly Induced Dynamic N uclear P o l a r i z a t i o n (CIDNP)

A few r e p o r t s have r e c e n t l y appeared d e s c r i b i n g e m is s io n nmr

(CIDNP) s p e c tr a o f compounds d e r iv e d from r a d i c a l p r e c u r so r s (Bargon,

F is c h e r , and Johnsen 1967, Ward and Lawler 1967, Lawler 1967, K aptein

and Sekuur 1 9 6 8 ) . In p a r t i c u l a r , Ward and L a w ler 's r e p o r t th a t n-

b u t y l l i t h iu m and n - b u t y l bromide r e a c t in e th e r -h e x a n e to produce 1-

b utene and t h a t the p rod u ct g i v e s an nmr e m is s io n s i g n a l i n d i c a t e s a

r a d i c a l path f o r the r e a c t i o n as shown b e low .

n-BuLi 4- n -BuBr ------- —> 2 n-Bu • 4- LiBr

IC H 3CH2C = CL32

H

A ttem pts to d e t e c t an nmr e m is s io n s p e c tr a from the r e a c t io n

o f j > b u t y 11ithium-DPA-THEDA in c y c lo o c t a n e were n o t s u c c e s s f u l .

EXPERIMENTAL

M elt in g p o in t s were determ ined on a F is h e r "Johns or a Mel--Temp

apparatus and are u n c o r r e c t e d 0 N u clear m agn etic re so n a n ce (ntrxr) s p e c

tr a were determ ined on a Varian Model A~6Q (60MHz) s p e c tr o m e te r , u s in g

t e t r ame thy 1 s i lan e as an i n t e r n a l standard e E i th e r a P erk in ■"-Elmer

In fra co rd or a Beckman IR-4 sp e c tr o p h o to m ete r was used to determ in e

in fr a r e d s p e c tr a ; a p o ly s t y r e n e f i l m was used to c a l i b r a t e the i n s t r u - .

ments 'o ‘ ; '•

M ic r o a n a ly ses were performed - by th e M icro-T ech L a b o r a to r ie s , .

Sk ok ie , I l l i n o i s 0 Deuterium a n a ly s e s r e p o r te d as "atom % e x c e s s deu~

ter iu m ,f were performed by Joseph Nemeth, Urbana, I l l i n o i s , u s in g the

f a l l i n g drop m ethod; th o s e r e p o r te d as "deuterium atom per m o le c u le 11

were c a l c u l a t e d from mass s p e c tr a data* G a s - l iq u id phase chromatography

( g lp c ) was c a r r ie d ou t on an F & M Model 609 f lam e i o n i z a t i o n i n s t r u - ■

ment u s in g columns packed w ith GE-SE-30 on Chromosorb Wc For a n a l y t i

c a l g lp c d e t e r m in a t io n s , c o r r e c t i o n f a c t o r s f o r mole r a t i o / a r e a r a t i o

d ata were determ ined w ith s tan d ard s c o n t a in in g the same compounds as in

the unknown m ixtureo For i r r a d i a t i o n exp er im en ts a q u a r tz j a c k e t e d ,

Hanovia Type L, mercury arc lamp was used 0

Hexane and l i g r o i n e ( 9 0 -1 2 0 ° ) were p u r i f i e d by s t i r r i n g o v e r

n i g h t w i th 957o s u l f u r i c a c id , w ash ing w i t h d i s t i l l e d w a te r , d ry in g over

anhydrous magnesium s u l f a t e , and r -e f lu x in g over sodium m eta l f o r 24 hr

p r io r to f i n a l d i s t i l l a t i o n ,

43

.44

.M a ll in ck rod t . anhydrous r e a g e n t grade e th e r was used w i th o u t

f u r th e r p u r i f i c a t i o n * R eagent grade d io x a n e •was p u r i f i e d by d i s t i l l a

t i o n from l i t h iu m aluminum h yd r id es R eagent grade benzene was d r ied by

d i s t i l l i n g from c a lc iu m hydride* Reagent grade carbon t e t r a c h l o r i d e

was made anhydrous by s t i r r i n g w i th phosphorous p en to x id e*

R eagent grade n - b u t y l bromide was f u r th e r p u r i f i e d by d ry in g

over anhydrous sodium carb on ate and d i s t i l l i n g under a n i t r o g e n atm os

phere* Eastman Grade N9N9N??Nf ~ te tr a m e th y le th y le n e d ia m in e (TMEDA) was

f u r th e r p u r i f i e d and d r ie d by d i s t i l l i n g from c a lc iu m h y d r id e and s t o r

in g over p o ta ss iu m h y d r o x id e 0

Deuterium o x id e was o b ta in ed from S t o h le r I s o to p e Chemicals and

c o n ta in ed 9 9 e8 atom % deuterium s Deuterium c h lo r id e was prepared by

the a d d i t io n o f deuterium o x id e to b e n z o y l c h lo r id e (Brown and Groot

1 9 4 2 ) .

D ip h e n y la c e ty le n e (DBA) was s y n t h e s i z e d from b e n z i l and h yd ra

z in e h y d ra te (Cope, Sm ith, and C otter 1 9 6 3 ) . 'l -P h en y lp ro p y n e was ob

ta in e d from Columbia Organic Chem icals Company and was s to r e d a t 2°

u n t i l d i s t i l l a t i o n im m ed ia te ly p r io r to u s e . A u th e n t ic t r i p h e n y l -

e th y le n e was prepared from benzophenone and b e n z y l magnesium bromide

(Adkins and Zartman 1 9 4 3 ) . B ro m o tr ip h e n y ie th y le n e . was s y n t h e s iz e d from

t r ip h e n y le t h y le n e and bromine (A p e lg o t e t a l* 1 9 5 2 ) e

Lithium w ir e and t ^ b u t y l l i t h iu m in pentane were o b ta in ed from

the L ithium C orp ora tion o f Am erica. n - B u t y l l i t h iu m in hexane was ob

ta in e d from Foote M ineral Company,. .n -B u ty l- l i th iu m '.in e t h e r was s y n t h e

s i z e d from n - b u t y l bromide and l i t h iu m (Jon es and Gilman 1951) in 90-

95% y i e l d as determ ined b y . the doub le t i t r a t i o n method (Gilman and

45Haubein 1 9 4 4 ) 0 A l l o r g a n o l i th iu m r e a c t i o n s were run under a n i t r o g e n

atm osphere in f la m e -d r ie d apparatus p r o t e c t e d by c a lc iu m c h lo r id e dry

in g tubeso

& ~ B u ty ll i th iu m and DPA D e u t e r o l y s i s

In Ethero The procedure was t h a t o f S 6 Gardlund ( 1 9 6 3 ) 0 To a

s o l u t i o n o f n - b u t y l l i t h i u m ( 0 ,6 2 m ol) in 500 ml o f e th e r th e r e was

added r a p i d ly DPA (60 g , O034 m ol) in 200 ml o f e t h e r 0 A f t e r s t i r r i n g

a t room tem perature f o r 20 h r 9 the dark red s o l u t i o n was t r e a t e d w i th

d euter ium o x id e (18 g P 0 o90 m ol) w h i l e m a in ta in in g th e tem perature a t

5° by e x t e r n a l c o o l i n g 0 The r e a c t i o n m ix tu re was s t i r r e d f o r an a d d i

t i o n a l 2 hr and 60 ml o f w ater added; the e th e r la y e r was sep a ra ted and

d r ied (MgSO^) 0 ' .

C o n ce n tr a t io n o f the e th e r l e f t a y e l lo w o i l w h ich , a f t e r th r e e

d i s t i l l a t i o n s through a sm a ll V igreaux column, gave 9 o0 g (11%) o f g lp c

pure d e u te r a te d t r a n s - C X - n - b u t y l s t i lb e n e s bp 105-107° ( 0 o15 mm); nmr

(10% CCl^) T 2 .4 - 2 * 8 (m, 9*1 , a ro m a tic ) 7 , 1 - 7 , 5 ( t , 2 . 0 , CH^CH^C),

8 . 4 - 9 . 3 (m, 7 . 0 , CH^CH^CH^CH^).

A n a l. C a l c d o f o r D,. 10 .0 0 atom % e x c e s s deuter iu m .

Found: D, 9 .5 0 atom % e x c e s s d e u te r iu m 6

The f i r s t f r a c t i o n from the f i r s t d i s t i l l a t i o n was r e c r y s t a l

l i z e d t h r e e t im es from 95% e th a n o l to g i v e g lp c pure d e u te r a te d d i -

p h e n y la c e t y l e n e , mp 5 9 - 6 0 ° .

A n a l. C a lcd . f o r C^^H^D: D, 1 0 .0 0 atom % e x c e s s deuterium®

Found: D, 2 .8 5 atom % e x c e s s d eu ter iu m .

46In Hexane9 TMEDA0 n - B u t y l l i t h iu m ( 0 o25 m ol) in 150 ml o f h e x

ane was added s lo w ly to a s t i r r e d s o l u t i o n of, DPA ( 1 7 08 g 9 0*100 mol)

and TMEDA ( 2 9 e0 g ? 0*250 m ol) a t -2 0 °* ' The s o l u t i o n was a llow ed to

warm to room tem perature and s t i r r e d f o r 16 hr* The dark red r e a c t io n

m ix t u r e ? c o n t a in in g a c o n s id e r a b le amount o f y e l l o w p r e c i p i t a t e , was

c o o le d to 5° and deu ter iu m o x id e (10*0 g , 0*500 mol), was added s low ly*

The m ix tu re was s t i r r e d f o r an a d d i t i o n a l 4 hr a t room t e m p e r a t u r e 100

ml o f w ater was added and th e la y e r s were s e p a r a t e d c The o r g a n ic la y e r

was d r ied (Na^SO^) and c o n c e n tr a te d to g iv e 2 2 c1 g o f a dark red o i l *

D i s t i l l a t i o n through a s m a ll V igreaux column y i e l d e d 16*4 g (69%)of

g lp c pure d e u te r a te d t r a n s - O c - n - b u t y l s t i l b e n e g bp 113-115° ( 0 ,2 5 mm).

The nmr spectrum and the g lp c r e t e n t i o n ' time o f the p rod u ct were id e n

t i c a l w i th th o se o f t r a n s ~ C X ~ n -b u ty ls t i lb e n e prepared in e th er*

A n a l, Calcd.o f o r C^gH^gD^s D, 10 ,0 0 atom % e x c e s s deuterium .

Pounds D, 9 ,5 5 atom % e x c e s s d eu ter iu m .

Lithium D e u te r o x id e 9 D e u te r iu m O xide9 and DPA

Deuterium o x id e ( 0 ,9 0 g 5 0 ,0 4 5 m ol) was added s lo w ly to a

s t i r r e d s u s p e n s io n o f sm a ll p i e c e s o f l i t h iu m w ir e ( 0 ,1 6 g ? 0 ,0 2 3 m ol)

in 12 ml o f anhydrous e th e r w h i l e m a in ta in in g a tem peratu re o f 5 ° , The

m ixtu re was a l lo w ed to warm to room tem perature and s t i r r e d f o r 24 hr

to a s s u r e com p lete fo rm a t io n o f l i t h iu m d e u t e r o x id e , DPA ( 3 ,0 g ,

0 ,0 1 7 m ol) was added and the m ix tu re was s t i r r e d f o r an a d d i t io n a l 16

hr* Water (10 ml) was added and th e l a y e r s were s e p a r a te d . The e th e r

la y e r was d r ied (Na^SO^) and c o n c e n tr a te d to g iv e a q u a n t i t a t i v e r e c o v

ery o f DPA; mp 5 9 ,5 -6 0 % a f t e r two r e c r y s t a l l i z a t i o n s from 95% e t h a n o l ,

47

Analo Founds D? 0 .0 0 atom % e x c e s s d eu ter iu m .

Anhydride o f 2~Phenyl”3 ^ carboxypheny l )~ 2 ~ h e p t e n o ic Acid

The r e a c t io n w a s .ru n i n the manner d e s c r ib e d by Ze Gardlund

( 1 9 6 4 ) e T h ion y l c h lo r id e ( 6 08 g 9 0 o057 m ol) was added in one p o r t io n

to a r a p id ly s t i r r e d s u s p e n s io n o f 2»7 g ( 8 .3 mmol) o f t r a n s - 2- pheny1-

3“ (£“carbox y p h e n y l ) « 2 - h e p t e n ° i c a c id (S . Gardlund 1963) in 60 ml o f an

hydrous carbon t e t r a c h l o r i d e and the m ix tu re was r e f lu x e d f o r 5 h r .

The c l e a r y e l l o w s o l u t i o n was a l low ed to c o o l to room tem perature

poured i n t o 400 ml o f i c e w a te r , and s t i r r e d f o r 45 m in 0 E ther (200

ml) was added and the la y e r s were s e p a r a t e d . The o r g a n ic la y e r was

e x tr a c t e d w i th th r e e 25-ml p o r t io n s o f s a tu r a te d aqueous sodium c a r

bon ate s o l u t i o n and d r ie d (Na^SO^). A f t e r c o n c e n t r a t io n o f the o r g a n ic

l a y e r , 1 ,6 2 g (94%) o f crude anhydride rem ainede F iv e r e c r y s t a l l i z a

t i o n s from hexane produced w h ite c r y s t a l s w i t h mp 8 9 ,5 - 9 0 ° ; nmr (20%

CDClg) T 2 , 0 - 2 , 7 (m, 9 . 0 , a r o m a t ic ) , 7 . 2 - 7 . 6 ( t , 1 .9 , CH^CH^C), 8 . 6 -

9«5 (ms 7„0, .CH3 CH2CH2CH2 )$ i r (CHC1 ) 1785 (C O ) and 1750 c irf1 ' ( C O ) c

A n al. Calcdo f o r ^20^18^3S 7 8 .4 0 ; Hs 5 .9 2 ; mol w t 306 .

Found; C, 7 8 .3 4 ; H, 5 .9 8 ; mol w t 331 .

■ t > B u t y l l i t h iu m s TMEDA, and DBA

T erm ination o f .R eact ion by C a r b o n a tio n . t .-B uty l l i t h iu m ( 0 .3 5

, m ol) in 250 ml o f pentane was added s lo w ly to a s t i r r e d s o l u t i o n o f

DPA ( 2 5 .0 g , 0 .1 4 0 m ol) and TMEDA ( 4 0 .6 g , 0 .3 5 0 m ol) w h i l e m a in ta in in g

a tem perature o f 5° by e x t e r n a l c o o l i n g . A f t e r s t i r r i n g f o r 22 hr

under r e f l u x ( 4 3 ° ) , the dark red r e a c t i o n m ix tu re was carbonated by

48d e c a n t a t io n i n t o powdered Dry I c e . The m ixtu re was a l lo w ed to stand

o v e r n ig h t b e fo r e 1 1. o f w ater was added . The r e s u l t i n g b a s i c s o l u t i o n

was e x tr a c t e d w ith e th e r and the la y e r s s e p a r a te d . The n e u t r a l e th e r

l a y e r was d r ie d (Na^SO^) and c o n c e n tr a te d to g iv e 9 .3 g o f a dark red

o i l . D i s t i l l a t i o n o f the o i l gave 2 .1 g ( 6%) o f c i s - C X - t - b u t y l s t i l -

bene: mp 4 9 .5 - 5 0 ° , a m ix tu re m e l t in g p o in t w ith an a u t h e n t ic sample was

un d ep ressed ; nmr (40% CDCl^) T 2 .6 5 - 3 .4 0 (m, 9 . 7 , a r o m a t ic ) , 3 .4 5 ( s ,

1 .0 , CH), 8 .8 5 ( s , 9 . 0 , j > B u ) . There was a l s o o b ta in ed 2 .6 g o f an

orange o i l [bp 120-150 ( 0 . 1 mm)) which g lp c a n a l y s i s showed to c o n ta in

c i s -C X -t -b u ty l s t i l b e n e and about 20% 2 - t - b u t y l - 3 - p h e n y l i n d o n e . T his

corresp on d s to a 1,3% y i e l d o f the indone based on DPA. The rem ain ing

4 .6 g was u n d is t i l l a b l e .

The b a s i c aqueous s o l u t i o n was a c i d i f i e d w i th 6 M h y d r o c h lo r ic

a c id and e x t r a c t e d w i t h e t h e r . The e t h e r was d r ied (Na2S0^) and con

c e n tr a te d to y i e l d 4 2 ,0 g o f y e l l o w a c i d i c m a t e r ia l . Two r e c r y s t a l l i

z a t i o n s from hexane gave 1 6 .2 g (41%) o f c i s - 4 , 4 - d i m e t h y l - 2 , 3 -d ip h e n y l -

2 - p e n te n o ic a c id : mp 1 8 9 -1 9 0 °; nmr ( 8% CDCl^) T 2 . 6 - 3 . 0 (m, 1 0 .0 ,

a r o m a t ic ) , 8 .7 ( s , 9 . 0 , t - B u ) .

T erm ination o f R e a c t io n by D e u t e r o l y s i s . t - B u t y l l i t h i u m ( 0 .3 5

m ol) in 227 ml o f pentane was added s lo w ly to a s t i r r e d s o l u t i o n o f DPA

( 2 5 .0 g , 0 .1 4 0 m ol) and TMEDA ( 4 0 .6 g , 0 .3 5 0 m o l ) . A f t e r s t i r r i n g

under r e f l u x ( 4 3 ° ) f o r 6 hr the r e a c t i o n m ixture was t r e a t e d s lo w ly

w ith deuterium o x id e ( 2 0 .0 g , 1 .0 0 m ol) w h i l e m a in ta in in g a tem perature

o f a p p ro x im a te ly 5° by e x t e r n a l c o o l i n g . The m ixtu re was s t i r r e d f o r

an a d d i t io n a l 12 hr a t room tem p era tu re , 100 ml o f w a te r added, and the

49l a y e r s s e p a r a t e d . The o r g a n ic la y e r was d r ied (Na^SO^) and con cen

t r a te d to g i v e 3 4 .2 g o f a dark red o i l , w hich was shown by g lp c to

c o n t a in 14% DPA, 74% c i s - C X - t - b u t y l s t i l b e n e , and 12% t r a n s - Q L -t-b u ty 1-

s t i l b e n e . The a d d i t io n o f a seed c r y s t a l o f c i s - Q t - t - b u t y l s t i l b e n e

caused s o l i d i f i c a t i o n o f the o i l . The s o l i d was f i l t e r e d , r e c r y s t a l

l i z e d tw ic e from 95% e th a n o l and sublim ed to g iv e 1 6 .2 g ( 49%) o f g lp c

pure d e u te r a te d c i s - o t - t - b u t y l s t i l b e n e : mp 5 0 .5 ° , a m ix tu re m e l t in g

p o in t w i th a u t h e n t ic sample (Carr 1966) was u n d e p r e sse d ; nmr (30%

CDClg) T 2 .6 5 - 3 ,4 5 (m, 1 0 .0 , a r o m a t ic ) , 8 .8 3 ( s , 9 .0 Jt-Bu).

A n a l . C alcd . f o r C^gH^D: D, 5 .0 0 atom % e x c e s s deu ter iu m .

Found: D, 4 .9 5 atom % e x c e s s d eu ter iu m .

A p o r t io n o f the f i l t r a t e was f r a c t io n a t e d through a p rep ara

t i v e s c a l e g a s - l i q u i d phase chrom atograph. The f i r s t and th ir d compon

e n t s were c o l l e c t e d to g iv e d e u te r a te d DPA and d e u te r a te d t r a n s -C X -t-

b u t y l s t i l b e n e , r e s p e c t i v e l y .

The d e u te r a te d DPA was r e c r y s t a l l i z e d tw ice from 95% e th a n o l to

y i e l d g lp c pure p rod u ct: mp 5 9 - 6 0 ° , a m ix tu re m e l t in g p o i n t w ith a u th en

t i c sample was u n d ep re sse d .

A n a l. C a lcd . f o r C^^HgD^: D, 2 .0 0 atom per m o le c u le . Found:

D, 1 .79 atom per m o le c u le .

The d e u te r a te d t r a n s - c x - t - b u t y 1 s t i lb e n e was r e c r y s t a l l i z e d from

95% e th a n o l and sublim ed to y i e l d g lp c pure product: mp 4 1 ° , a m ixture

m e l t in g p o i n t w i t h a u t h e n t ic sample (Carr 1966) was u n d ep ressed ; nmr

(30% CC1 ) T 2 .8 0 ( s , 9 . 7 , a r o m a t ic ) , 9 .0 0 (