Enantioselective Organocatalytic Michael Addition of Malonates to α,β-Unsaturated Ketones
作者:Pengfei Li、Shigang Wen、Feng Yu、Qiaoxia Liu、Wenjun Li、Yongcan Wang、Xinmiao Liang、Jinxing Ye
DOI:10.1021/ol802892h
日期:2009.2.5
derived from 1,2-diaminocyclohexane and 9-amino (9-deoxy) cinchona alkaloid was developed into asymmetricMichaeladdition of malonates to enones. A series of cyclic and acyclic enones could react very well with different malonates in the presence of 4 with 0.5−10 mol % catalyst loading affording chiral Michael adducts with excellent yields and ee values.
Organocatalyzed highly stereoselective Michael addition of ketones to alkylidene malonates and nitroolefins using chiral primary-secondary diamine catalysts based on bispidine
based on bispidine have been developed to catalyze the asymmetric Michaeladdition of ketones to alkylidenemalonates and nitroalkenes. The corresponding products were obtained in high yields (up to 99%) with high diastereoselectivities (up to 99:1) and high enantioselectivities (up to 97% ee) under mild conditions using either environmentally benign water as the solvent or no solvent.