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Department of Chemistry Seminar Announcement
Date/Time/Venue
Title/Speaker
25 Jan (Tue) 11am – 12nn
@ S8 Level 3 Executive Classroom
Rh-Catalyzed [(5+2)+1], [7+1], Rh-Catalyzed [(5+2)+1], [7+1], [3+2], and [(3+2)+1] [3+2], and [(3+2)+1] CycloadditionsCycloadditions
Professor Yu ZhixiangPeking University, ChinaHost : Asst Prof Wang JianAbout the Speaker
All are Welcome
Prof. Zhi-Xiang Yu (1991, B.S., Wuhan University; 1997, M.S., Peking University; 2001, Ph. D., Hong Kong University of Science & Technology; 2001-2004, Postdoctoral associate, University of California, Los Angeles) started his independent career as an associate professor at Peking University in 2004 and was promoted to a full professor in 2008. He and his group are applying both computational and synthetic organic chemistry to study reaction mechanisms, to discover, design and develop new reactions, and to synthesize natural products. Prof. Yu is one of the National Science Fund for Distinguished Young Scholars of China in 2008 and won the Young Chemist Award, the Chinese Chemical Society & the Royal Society of Chemistry in 2008.Abstract
X X
H
H
X X
H
X X
HO
Rh Rh
X Xn n
Rh
Rh+ CO
[3+2]
[3+2] [3+2]
[(3+2)+1]
J. Am. Chem. Soc, 2008, 130, 7178.
Org. Lett., 2010, 12, 1332.
Chem. Comm. 2010, 46, 1059.J. Am. Chem. Soc, 2011, ASAP.
Org. Lett., 2010, 12, 2528.
XR1
X
R1
O
OR2
R2+ 2 COformal
[5+1]/[2+2+1]
Rh
J. Am. Chem. Soc, 2011, accepted.
Rh Rh+ CO
[(5+2)+1] [7+1]
Org. Lett., 2011, 13, 134.R2
R2
O
R1
R1
O
J. Am. Chem. Soc., 2007, 129, 10060.Chem. Asian. J. 2010, 5, 1555.
+ CO
H
H
O
O
O
H
H
H
H H
H
O
OHO2C
H
H
O
OH
COC
OMe
MeO2CMeO2C Me
Me
MeO
+[(3+2)+1]
Discovering and developing transition metal catalyzed [m+n], [m+n+o], [m+n+o+x] cycloadditions to reach various cyclic compounds are important for the “ideal synthesis” of functional molecules, which usually have various-sized ring skeletons that are not easy or difficult to be accessed by the traditional organic reactions. Recently we developed several rhodium catalyzed cycloaddition reactions of vinylcyclopropanes with alkynes, alkenes, allenes, and CO to construct five-, six-, and
eight-membered carbocycles with the aid of calculations (see these [(5+2)+1], [7+1], [3+2], and [(3+2)+1] cycloadditions in the scheme below). Some of these reactions have been applied to the synthesis of natural products to demonstrate the impacts of these cycloaddition reactions on synthesis.
Department of Chemistry Seminar Announcement
Date/Time/Venue
Title/Speaker
27 Jan (Thu) 3pm – 4pm
@ S8 Level 3 Executive Classroom
Water Catalysis in [1,n]-Water Catalysis in [1,n]-Hydrogen ShiftsHydrogen Shifts
Professor Yu ZhixiangPeking University, ChinaHost : Assoc Prof Lu Yixin
About the Speaker
All are Welcome
Prof. Zhi-Xiang Yu (1991, B.S., Wuhan University; 1997, M.S., Peking University; 2001, Ph. D., Hong Kong University of Science & Technology; 2001-2004, Postdoctoral associate, University of California, Los Angeles) started his independent career as an associate professor at Peking University in 2004 and was promoted to a full professor in 2008. He and his group are applying both computational and synthetic organic chemistry to study reaction mechanisms, to discover, design and develop new reactions, and to synthesize natural products. Prof. Yu is one of the National Science Fund for Distinguished Young Scholars of China in 2008 and won the Young Chemist Award, the Chinese Chemical Society & the Royal Society of Chemistry in 2008.Abstract[1,n]-hydrogen shifts are widely found in organic and enzymatic reactions. However, details of their reaction mechanisms are usually not available. Some [1,n]-hydrogen shifts are difficult to occur, as judged from the orbital interaction and symmetry considerations. In these cases, some “mysterious” catalysts must play roles to catalyze these [1,n]-hydrogen shifts. In this talk, through several examples,1-5 we want to show that the inadvertent water in the organic reaction systems, or the water solvent itself in aqueous reaction systems, can act as the “mysterious” catalyst to facilitate the otherwise difficult [1,n]-hydrogen shifts.
H H HOH
Protonation
H
Deprotonation
OH H
OH H
Black BoxReferences:1.Xia, Y., Liang, Y., Chen, Y., Wang, M., Jiao, L., Huang, F., Li, S., Li, Y., and Yu, Z.-X., J. Am. Chem. Soc. 2007, 129, 3470. 2.Liang, Y., Liu, S., Xia, Y., Li Y., Yu, Z.-X. Chem. Eur. J. 2008, 14, 4361.3.Shi, F., Li, X., Xia, Y., Zhang, L., Yu, Z.-X., J. Am. Chem. Soc. 2007, 129, 15503.4.Liang Y.; Liu S., Yu, Z.-X. Synlett, 2009, 905.5.Liang Y., Zhou, H. Yu, Z.-X. J. Am. Chem. Soc. 2009, 131, 17783.