Synfacts 2009(3): 0331-0331  
DOI: 10.1055/s-0028-1087730
Organo- and Biocatalysis
© Georg Thieme Verlag Stuttgart ˙ New York

Bifunctional Cinchona Sulfonamides in Asymmetric Michael Reaction

Contributor(s): Benjamin List, Olga Lifchits
J. Luo, L.-W. Xu, R. A. S. Hay, Y. Lu*
National University of Singapore, Singapore and Hangzhou Normal University, P. R. of China
Further Information

Publication History

Publication Date:
19 February 2009 (online)

Significance

A novel bifunctional catalyst 1, which uses the cinchona alkaloid core as the ­stereocontrolling element and an N-sulfonamide moiety for single hydrogen-bonding catalysis, was employed in an enantioselective Michael addition. This quaternary carbon-forming reaction afforded the products in excellent yields and enantioselectivities, though diastereoselectivity was generally moderate. The catalyst is thought to activate both the nucleophile and the electrophile by hydrogen bonding with the quinuclidine nitrogen and the N-sulfonamide group, respectively.