Enantioselective Pd-Catalyzed Allylic Substitution using Phosphite-Oxazoline PHOX-Based Ligands containing a Methylene Linker

Abstract

High enantioselectivities (up to 99 %) and activities (TOF's up to >4000 h−1) are accomplished in the Pd-catalyzed allylic substitution of a wide range of substrate types and nucleophiles using a family of phosphite-oxazoline ligands. These ligands were derived from the PHOX ligand by exchanging the phosphine moieties by biaryl phosphites and a methylene spacer was introduced between the oxazoline and the phenyl ring. The wide substrate scope is due to the ability of the ligand family to adapt their ligand parameters to the reacting substrate. This ability also explains its high performance in other type of catalytic processes.