Regio- and stereoselective alternating copolymerization of α-olefins with carbon monoxide using a cationic palladium-chiral diphosphine catalyst

Enantioselective alternating copolymerization of carbon monoxide with propylene, 1-heptene, 1-octene, and styrene was carried out using a palladium catalyst modified by 1,4-3,6-dianhydro-2,5-dideoxy-2,5-bis(diphenylphosphino)-l-iditol (DDPPI). The pure poly(1,4-ketone)s were obtained by dissolving the copolymers containing spiroketal and 1,4-ketone units in 1,1,1,3,3,3-hexafluoro-2-propanol and reprecipitating with methanol. Optical rotation, elemental analysis and 1H, 13C NMR and IR spectra showed that our copolymers were optically active and isotactic with an alternating poly(1,4-ketone) structure.