Copolymerization of carbon monoxide withexo-methylenecycloalkane and dienes: synthesis of functionalized aliphatic polyketones

Synthesis of functional aliphatic polyketones was achieved by co- and terpolymerization of the strained exo-methylenecycloalkane, methylenecyclopropane (MCP), and also the dienes 1,5-hexadiene, 1,7-octadiene and 1,6-heptadien-4-ol, with carbon monoxide and propene, using the dicationic palladium(II) phosphine complex [Pd(dppp) (NCCH3)2](BF4)2 (I) (dppp is 1,3-bis(diphenyl-phosphino)propane) as the catalyst precursor. The resulting MCP/CO copolymer contains both ring-opened and cyclic microstructures. Ring-opening copolymerization yields exo-methylene functionalized polyketone. In contrast to hexadiene/carbon monoxide copolymer (Hx/CO), no ring structures were observed in the alternating octadiene/carbon monoxide (Oc/CO) and heptadien-4-ol/carbon monoxide (Hp-ol/CO) copolymers. The remaining double bonds were left intact to yield polymers with olefinic functionalities in the side chains. © 2001 Society of Chemical Industry