Chiral ligands used in transition metal catalysts for asymmetric addition reactions especially hydrogenation

Abstract

Ligands of the formula (I) secondary phosphine-Q-P(═O)HR(I) in the form of mixtures of diastereomers or pure diastereomers, in which secondary phosphine is a secondary phosphine group with hydrocarbon radicals or heterohydrocarbon radicals as substituents; Q is a bivalent bisaryl or bisheteroaryl radical with an axial chiral centre to which the two phosphorus atoms are bonded in the ortho positions to the bisaryl or bisheteroaryl bridge bond, or Q is a bivalent ferrocenyl radical with a planar chiral centre or without a planar chiral centre, to which the phosphorus atom of the secondary phosphine is bonded directly or via a C-C-carbon chain to a cyclopentadienyl ring, the —P*(═O)HRgroup is bonded either on the same cyclopentadienyl ring in ortho position to the bonded secondary phosphine or on the other cyclopentadienyl ring; P* is a chiral phosphorus atom, and Ris a hydrocarbon radical, a heterohydrocarbon radical or a ferrocenyl radical, where Ris a ferrocenyl radical with a planar chiral centre when Q is a ferrocenyl radical without a planar chiral centre. Metal complexes of these ligands are homogeneous catalysts for asymmetric addition reactions, particularly hydrogenations.