Study of ligand and base effects on enantioselective allylation catalyzed by Pd(0) phosphine complexes in [bmim][PF6] ionic liquid

Abstract

Enantioselective Pd-catalyzed allylic substitution of (rac)-(E)-1,3-diphenyl-3-acetoxyprop-1-ene with dimethyl malonate was studied in 3-butyl-1-methylimidazolium hexafluorophosphate ([bmim][PF₆]) as an ionic liquid. The reactions were catalyzed by Pd(0) complexes of three homochiral ferrocenylphosphine ligands, (S,S)-iPr-Phosferrox, (S,R)-iPr-Phosferrox, (R,S)-BCyPFA and (R)-BINAP. Potassium carbonate and bis(trimethylsilyl)acetamide (BSA)/AcOK were tested as the bases and simple optimization of the reaction procedure was performed. Experiments with other soft nucleophiles also were carried out under optimized conditions.