Synfacts 2008(2): 0198-0198  
DOI: 10.1055/s-2007-992440
Organo- and Biocatalysis
© Georg Thieme Verlag Stuttgart · New York

Desymmetrization of Cyclohexanones Catalyzed by Chiral Ionic Liquids

Contributor(s): Benjamin List, Daniela Kampen
S. Luo*, L. Zhang, X. Mi, Y. Qiao, J.-P. Cheng*
Institute of Chemistry, Chinese Academy of Sciences, Beijing and Nankai University, Tianjin, P. R. of China
Further Information

Publication History

Publication Date:
23 January 2008 (online)


An organocatalytic desymmetrization of 4-substituted cyclohexanones (1) via Michael addition to nitroolefins (2) has been developed. Ketones 1 react with aromatic nitroalkenes 2 in the presence of chiral ionic liquid 3 (15 mol%) and salicylic acid (5 mol%) to give adducts of type 4 in high yields, diastereoselectivities and enantio­selectivities. This transformation presumably proceeds via an enamine intermediate. A transition state illustrating the mode of face shielding by the imidazolium moiety to explain the observed relative and absolute configuration is proposed.