Rhodium catalysts derived from a fluorinated phanephos ligand are highly active catalysts for direct asymmetric reductive amination of secondary amines

Abstract

An asymmetric hydrogenation of enamines is efficiently catalysed by rhodium complexed with a fluorinated version of the planar chiral paracyclophane-diphosphine ligand, Phanephos. This catalyst was shown to be very active, with examples operating at just 0.1 mol% of catalyst. This catalyst was then successfully adapted to Direct Asymmetric Reductive Amination, leading to the formation of several tertiary amines with moderate e.e., if activated ketone/amine partners are used.