Rhodium-catalyzed enantioselective hydrogenation using chiral monophosphonite ligands

Surprisingly high enantioselectivities in the Rh-catalyzed hydrogenation of itaconic acid dimethyl ester 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.