Asymmetric conjugate addition of nitroalkanes to enones with a chiral α-aminophosphonate catalyst

Chiral diethyl (2R)-tetrahydropyrro-2-ylphosphonate is an effective catalyst for the Michael addition of nitroalkanes to alpha,beta-unsaturated ketones. This Study revealed that the hydrate salt of this alpha-aminophosphonate was found to be a better catalytic species. Moderate to high enantioselectivities were achieved in reactions that tolerate various nitroalkanes and enones in the presence of low loading of both catalyst ( 10 mol %) and bulk base (25 mol %). (C) 2008 Published by Elsevier Ltd.