Novel Ferrocenyl Ligands with Planar and Central Chirality in Pd-Catalyzed Allylic Substitutions

摘要

The use of planar chiral ferrocenyl ligands bearing a stereogenic center in #beta#-position of the side chain was investigated in Pd-catalyzed enantioselective allylic substitutions. By employing 2.2 mol % of a P,S-ligand and 1.0 mol % of [Pd(#eta#~3-C_3H_5)Cl]_2, the alkylation of the standard test system (+-)-(E)-diphenyl-2-propenyl acetate using dimethylmalonate/BSA as nucleophile proceeded in quantitative yield with an ee of 97%, which is the best value reported so far in this reaction using a P,S-ligand.