High Asymmetric Induction with β-Turn-Derived Palladium Phosphine Complexes

Work toward the development of a bisphosphine ligand system for the palladium-catalyzed addition to cyclic allyl acetates is reported. A parallel approach using phosphine-containing amino acids in conjunction with natural amino acids was used to develop a selective ligand system. The ligand system was examined while attached to the polymer support as well as in solution. Selectivites with the difficult substrate 3-acetoxycyclopentene of up to 95% ee are reported.