Rhodium-catalyzed enantioselective hydrogenation using chiral monophosphonite ligands

Surprisingly high enantioselectivities in the Rh-catalyzed hydrogenation of itaconic acid dimethyl eater and methyl-2-acetamido acrylate are observed upon using chiral monophosphonite ligands derived from binaphthol (ee up to 94%). Although appropriate chelating diphosphonites are more effective, the easy modular synthesis of the chiral monophosphonites may allow for the optimization of a given asymmetric hydrogenation reaction. (C) 2000 Elsevier Science Ltd. All rights reserved.