Transcript Rh-Catalyzed [(5+2)+1], [7+1], [3+2], and [(3+2)+1] Cycloadditions

Department of Chemistry
Seminar Announcement
Date/Time/Venue
Title/Speaker
25 Jan (Tue)
11am – 12nn
Rh-Catalyzed [(5+2)+1], [7+1], [3+2],
and [(3+2)+1] Cycloadditions
@ S8 Level 3
Executive
Classroom
Professor Yu Zhixiang
Peking University, China
Host : Asst Prof Wang Jian
About the Speaker
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
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.
All are Welcome
Department of Chemistry
Seminar Announcement
Date/Time/Venue
Title/Speaker
27 Jan (Thu)
3pm – 4pm
Water Catalysis in [1,n]-Hydrogen
Shifts
@ S8 Level 3
Executive
Classroom
Professor Yu Zhixiang
Peking University, China
Host : Assoc Prof Lu Yixin
About the Speaker
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.
References:
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.
All are Welcome