1‐Alkoxy‐2,5‐diphenylphospholane and ‐phospholanium Salts in Rhodium‐Catalyzed Asymmetric Hydrogenation.

Abstract

Enantioselective syntheses O 00311-Alkoxy-2,5-diphenylphospholane and -phospholanium Salts in Rhodium-Catalyzed Asymmetric Hydrogenation. -Phosphinites (I), their phosphonium salts (II) and their rhodium complexes (III) are prepared in a few steps and examined in the asymmetric hydrogenation of alkenylamine (IV) and cinnamate (VI). Complex (IIIb) affords the best enantioselectivity (75% e.e.) at quantitative conversion of the cinnamate. The enantioselectivities obtained with the other ligands or preformed complexes are only moderate and similar for either the phosphinite, the salt or the preformed complex. -(GALLAND, A.; PARIS, J. M.; SCHLAMA, T.; GUILLOT, R.; FIAUD, J.-C.; TOFFANO*, M.; Eur.