A convenient pathway to Sm(II)‐mediated chemistry in ... · spectrophotometer (Applied Photophysics Ltd. Surrey, UK). Unless otherwise stated, reactions were performed under an

1

AconvenientpathwaytoSm(II)‐mediatedchemistryinacetonitrile

ToddMaisano,KevinE.Tempest,DhandapaniV.Sadasivam,andRobertA.Flowers,II*

DepartmentofChemistry,LehighUniversity,Bethlehem,Pennsylvania18064USA

Fax:(+011)610‐758‐6536,E‐mail:[email protected]

ElectronicSupplementaryInformation

ListofContent

1.ExperimentalDetails S3

2.UV‐visspectraofSmI2withincreasingequivalentsofHMPAinCH3CN S3

3.UV‐visspectraofSm(OTf)2withincreasingequivalentsofHMPAinCH3CN S4

4.UV‐visspectraofSm(OTf)2withincreasingequivalentsofHMPAinTHF S4

5.UV‐visspectraofSm(OTf)2andSmI2inMeCNwithoutadditive S5

6.ConductivityofSm(OTf)2andSmI2inTHF S6

7.DecayTraceoftheReductionof50mMBenzylBromidebySmI2inTHF S6

8.RateorderofthereductionofbenzylbromidebySmI2inTHF S7

9.RateconstantofthereductionofbenzylbromidebySmI2inTHF S7

10.RateorderofthereductionofbenzylbromidebySm(OTf)2inTHF S8

11.RateconstantofthereductionofbenzylbromidebySm(OTf)2inTHF S8

12.RateorderofthereductionofacetophenonebySm(OTf)2inTHF S9

13.RateconstantofthereductionofacetophenonebySm(OTf)2inTHF S9

14.RateorderofthereductionofbenzylbromidebySmI2inMeCN S10

15.RateconstantofthereductionofbenzylbromidebySmI2inMeCN S10

16.RateorderofthereductionofacetophenonebySmI2inMeCN S11

17.RateconstantofthereductionofacetophenonebySmI2inMeCN S11

Supplementary Material (ESI) for Organic & Biomolecular ChemistryThis journal is (c) The Royal Society of Chemistry 2011

2

18.RateorderofthereductionofbenzylbromidebySm(OTf)2inMeCN S12

19.RateconstantofthereductionofbenzylbromidebySm(OTf)2inMeCN S12

20.RateorderofthereductionofacetophenonebySm(OTf)2inMeCN S13

21.GenerationofSamarium(II)triflateinMeCN S13

21.Generalprocedureforthesynthesisof9‐Methylbicyclo[4.3.0]nonan‐1‐olS14

22.1HNMRspectraof9‐Methylbicyclo[4.3.0]nonan‐1‐ol S15

23.13CNMRspectraof9‐Methylbicyclo[4.3.0]nonan‐1‐ol S16

24.References S16


3

Materialsandmethod:THFandacetonitrilewerepurifiedwithaPureSolvsolventpurification

system from Innovative Technology Inc. Sm(OTf)3 was purchased from Alfa‐Aesar and used

withoutfurtherpurification.HMPAandDMPUwerepurifiedbydistillingovercalciumoxideand

degassed with argon and stored in Innovative Technology, Inc. drybox containing argon

atmosphere. UV‐vis experiments were performed with a Shimadzu UV‐1601 UV‐vis

SpectrophotometercontrolledbyUVProbe(version1.11)software.KineticexperimentsinTHF

andacetonitrilewereperformedwitha computer‐controlledSX‐18MVstopped‐flow reaction

spectrophotometer (AppliedPhotophysics Ltd. Surrey,UK).Unlessotherwise stated, reactions

wereperformedunderan inertatmosphereofargon.13C,and1HNMRspectrawererecorded

onaBruker500MHzspectrometer.ASatelliteFTIRfromThermo‐MattsonwasusedtoobtainIR

spectra.GC‐MSanalysiswasperformedwithanHP5890Series IIGasChromatographwithan

HPMassSelectorDetector.

UV‐visStudies:

FigureS1.UV‐visspectraofSmI2withincreasingequivalentsofHMPAinCH3CN,[SmI2]=1

mM


4

FigureS2.UV‐visspectraofSm(OTf)2withincreasingequivalentsofHMPAinCH3CN,

[Sm(OTf)2]=1mM

FigureS3.UV‐visspectraofSm(OTf)2withincreasingequivalentsofHMPAinTHF,[Sm(OTf)2]=

1mM


5

FigureS4.UV‐visspectraofSm(OTf)2andSmI2withnoadditive,[Sm(OTf)2]=1mM,[SmI2]=1

mM

ConductivityStudies:

Analytes:SmI2,Sm(OTf)2

Solvent:Acetonitrile;Additive:HMPA.

Instrument:OAKTONCON10Basicconductivity/TDSMeter

Procedure:

Calibration:Initiallytheinstrumentwascalibratedwithastandardsolutionofknown

conductivity.Thentheprobewasrinsedwithwaterandfinallywithacetonitrileseveraltimes

beforetakingmeasurements.

SmI2:ToSmI2/Sm(OTf)2(20mL,2.5mM)underargonflow,HMPAwasaddedsequentiallyand

conductivitywasmeasured.


6

ConductivityinTHF

FigureS5.ConductivityofSmI2andSm(OTf)2inTHFwithincreasingequivalentsofHMPA

Kinetics:SmI2‐THF‐Benzylbromide

FigureS6.RepresentativedecayofSmI2forthereductionofbenzylbromideunderpseudofirst‐orderconditionsasmonitoredat550nm.


7

FigureS7.Plotofln[benzylbromide]versuslnkobsforthereductionofbenzylbromidewithSmI2.Rateorderofbenzylbromide=0.99.SmI2=5mM;Benzylbromide=10‐40equiv.

FigureS8.Plotof[benzylbromide]versuskobsforthereductionofbenzylbromide.Rateconstantofforreductionofbenzylbromide=1.80±0.03M‐1s‐1.SmI2=5mM;Benzylbromide=10‐40equiv.


8

Sm(OTf)2‐THF‐Benzylbromide

FigureS9.Plotofln[Benzylbromide]versuslnkobsforthereductionofbenzylbromidewithSm(OTf)2.Rateorderofbenzylbromide=0.97.Sm(OTf)2=5mM;Benzylbromide=10‐40equiv.

FigureS10.Plotof[benzylbromide]versuskobsforthereductionofbenzylbromidewithSm(OTf)2.Rateconstantofforreductionofbenzylbromide=4.9±0.01x10‐1M‐1s‐1.SmI2=5mM;Benzylbromide=10‐40equiv.


9

Sm(OTf)2‐THF‐Acetophenone

Figure S11. Plot of ln[acetophenone] versus ln kobs for the reduction of acetophenone withSm(OTf)2.Rateorderofacetophenone=1.07.Sm(OTf)2=5mM;acetophenone=10‐40equiv.

FigureS12.Plotof[acetophenone]versuskobsforthereductionofacetophenonewithSm(OTf)2.Rateconstantofforreductionofacetophenone=3.29±0.2x101M‐1s‐1.Sm(OTf)2=5mM;acetophenone=10‐40equiv.


10

SmI2inacetonitrile‐Benzylbromide

FigureS13.Plotofln[Benzylbromide]versuslnkobsforthereductionofbenzylbromidewithSmI2.Rateorderofbenzylbromide=1.05±0.06.SmI2=5mM;Benzylbromide=10‐50equiv.

FigureS14.Plotof[benzylbromide]versuskobsforthereductionofbenzylbromidewithSmI2.Rateconstantofforreductionofbenzylbromide=1.12±0.05x10‐1M‐1s‐1.SmI2=5mM;Benzylbromide=10‐50equiv.


11

SmI2‐Acetonitrile‐Acetophenone

FigureS15.Plotofln[acetophenone]versuslnkobsforthereductionofacetophenonewithSmI2.Rateorderofacetophenone=1.04.SmI2=5mM;acetophenone=10‐50equiv.

FigureS16.Plotof[acetophenone]versuskobsforthereductionofacetophenonewithSmI2.Rateconstantofforreductionofacetophenone=1.76±0.2M‐1s‐1.SmI2=5mM;acetophenone=10‐50equiv.


12

Sm(OTf)2inAcetonitrile‐Benzylbromide

FigureS17.Plotofln[Benzylbromide]versuslnkobsforthereductionofbenzylbromidewithSm(OTf)2.Sm(OTf)2=5mM;Benzylbromide=10‐50equiv.

FigureS18.Plotof[benzylbromide]versuskobsforthereductionofbenzylbromidewithSm(OTf)2.Rateconstantofforreductionofbenzylbromide=1.22±0.02x10‐1M‐1s‐1.Sm(OTf)2=5mM;Benzylbromide=10‐50equiv.


13

Sm(OTf)2inAcetonitrile‐Acetophenone

FigureS19.Plotofln[Acetophenone]versuslnkobsforthereductionofacetophenonewithSm(OTf)2.Sm(OTf)2=5mM;Benzylbromide=10‐50equiv.

GenerationofSm(OTf)2:

Samariumpowder(40meshsize,0.265g,1.76mmol),Sm(OTf)3(1.03g,1.72mmol),andiodine

(0.102g,0.4mmol)wereaddedto20mLofdryCH3CNinaflame‐driedvial.Thesolutionwas

thenstirredinsidegloveboxatroomtemperaturefor3hrs.AdarkgreensolutionofSm(OTf)2

wasobtainedwithconcentrationsintherangeof0.090.10M.Theconcentrationofthesolution

wasdeterminedbyiodometrictitration.


14

Cyclizationofolefinicketone:

2‐(3‐Butenyl) cyclohexan‐1‐one (1): Compound 1was synthesized using previously described

procedure.s1 1HNMR (500MHz,CDCl3)δ5.79‐5.71 (m,1H),4.99‐4.90 (m,2H),2.34‐1.20 (m,

13H).

Representativeprocedureforcyclizationreaction:

To a flame dried 50mL round bottomed flask, 9.31mL of Sm(OTf)2 (0.09M, 0.82mmol, 2.5

equiv)wasadded.Tothisa2mLacetonitrilesolutionofHMPA/additive(0.143mL,8.2mmol,10

equivw.r.toSm(OTf)2)wasaddedunderstirring.Thiswasfollowedbydrop‐wiseadditionof2

mLacetonitrilesolutionofcyclicalkene(3)(0.050g,0.33mmol)andthemixturewascontinued

to stir inside the glove box until the completion of reaction. The reaction was quenched by

opening to air followed by addition of 10 mL of saturated NH4Cl. The aqueous layer was

extractedwith3X25mLetherandcombinedorganic layerwaswashedwithwaterandbrine

anddriedovermagnesiumsulphate.Thedriedorganiclayerwasconcentratedin vacuoandthe

crude product was analyzed by NMR. The products were identified by comparison with

publisheddata.S1

9‐Methylbicyclo[4.3.0]nonan‐1‐ol(2):1H‐NMR(500MHz,CDCl3)δ1.12‐1.89(m,15H),0.84(d,J=6.4Hz,3H);13C‐NMR(125MHz,

CDCl3)δ78.19,45.41,44.74,28.18,27.61,24.16,23.46,21.15,20.36,12.66;IRν3398,2932,

2871,1459,1006;LRMSm/z154(M+,18%),111(100%),98(90%),83(37%),55(73%).


15

1H‐NMRSpectrumof2:


16

13C‐NMRSpectrumof2:

References:

S1.Molander, G. A.; Mckie, J. A. J. Org. Chem. 1992, 57, 3132‐3139.


Documents

A convenient pathway to Sm(II)‐mediated chemistry in ... · spectrophotometer (Applied Photophysics Ltd. Surrey, UK). Unless otherwise stated, reactions were performed under an