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

Enantioselective alternating copolymerization of carbon monoxide with propy lene, 1-heptene, 1-octene, and styrene was carried out using a palladium ca talyst 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-he xafluoro-2-propanol and reprecipitating with methanol. Optical rotation, el emental analysis and H-1, C-13 NMR and IR spectra showed that our copolymer s were optically active and isotactic with an alternating poly(l,4-ketone) structure. (C) 2001 Elsevier Science Ltd. All rights reserved.