Highly asymmetric Michael additions of α,α-disubstituted aldehydes to β-nitroalkenes promoted by chiral pyrrolidine-thiourea bifunctional catalysts

A series of secondary amine-thiourea catalysts derived from L-proline and chiral diamine were prepared and first applied to the Michael addition of alpha,alpha-disubstituted aldehydes to trans-beta-nitroalkenes. Moderate yields (47-75%) and excellent enantioselectivities (up to 96% cc) were obtained for a variety of aryl and heteroaryl nitroalkenes. (C) 2010 Elsevier Ltd. All rights reserved.