Novel chiral P,O-ligands for homogeneous Pd(0) catalysed asymmetric allylic alkylation reactions

Two novel P,O-coordinating chiral phoshine-amide ligands with hydroxymethyl side chains 5a and 5b were prepared and tested in some benchmark Pd(0) catalysed asymmetric allylic alkylations. The conversions and enantioselectivities were generally good, with a highest conversion of 92% and a highest ee of 62% obtained using 1,3-diphenylpropenyl acetate as substrate. A number of palladium pre-catalysts were used, but it was [Pd(allyl)Cl]2 which gave the best results. Ligand 5b was seen to give better enantioselectivities.