Enantioselective hydrogenation of itaconate using rhodium bihelicenol phosphite complex. Matched/mismatched phenomena between helical and axial chirality

Phosphites prepared from bihelicenol, menthol (or 1-phenylethanol), and PCl3 are effective ligands for the rhodium-catalyzed enantioselective hydrogenation of dimethyl itaconate. Stereochemistry of the helicene moiety plays an important role in the asymmetric induction, and matched/mismatched phenomena are observed between helical and axial chirality. (C) 2003 Elsevier Science Ltd. All rights reserved.