Highly efficient bifunctional organocatalysts for the asymmetric Michael addition of ketones to nitroolefins

A type of secondary-secondary-tertiary triamine bifunctional organocatalysts have been properly designed and synthesized. In our study, the designed catalyst (S)-N-(pyrrolidin-2-ylmethyl)pyridin-2-amine 5 has been shown to be highly efficient to promote the asymmetric Michael addition of ketones to nitroolefins at room temperature, which afforded the corresponding adducts in excellent diastereoselectivities (up to 99:1 dr) and enantioselectivities (up to > 99% ee). (C) 2011 Elsevier Ltd. All rights reserved.