Asymmetric hydrophosphonylation of aldehydes catalyzed by bifunctional chiral Al(III) complexes

A new bifunctional chiral AI(III) complex of BINOL derivative, which contained tert-amine at 3,3'-position of the BINOL, has been developed for the effective enantioselective hydrophosphonylation of aldehydes. A variety of aromatic, heteroaromatic, condensed-ring, alpha,beta-unsaturated, and aliphatic aldehydes were found to be suitable substrates for the reaction, and the desired alpha-hydroxy phosphonate were obtained in good to excellent yields (up to 99%) with moderate to good enantioselectivities (up to 87% ee) under mild conditions (at 0 degrees C). A possible catalytic cycle based on the experimental results was proposed. (C) 2008 Elsevier Ltd. All rights reserved.