Enantioselective dicarbonylation of styrene to isotactic poly[1-oxo-2-phenylpropane-1,3-diyl] with phosphinodihydrooxazole-palladium(II) complexes: Model studies for enantioface selection

The first steps, believed to be involved in the highly enantioselective copolymerization of styrene and carbon monoxide to poly[1-oxo-2-phenylpropane-1,3-diyl] with phosphinodihydrooxazole-palladium(II) complexes, were investigated. The insertion of carbon monoxide into [Pd(Me)(P<^>N)(solvent)] TfO (P<^>N = (S)-2-[2-(5H-benzo[b]phosphindol-5-yl)phenyl]-4-benzyl-4,5-dihydrooxazole (1)) and of styrene into [Pd(COMe)(P<^>N)(solvent)] TfO were highly regioselective (alkyl and acyl substituents trans to N); moreover, the olefin insertion took place with essentially complete enantioface discrimination.