Design and synthesis of polymerizable cumulated double bond system. Living coordination polymerization of alkylallenes by pi-allylnickel catalyst

The coordination polymerization of monoalkylallenes (2a; 1,2-nonadiene, 2b; 1,2-heptadiene, 2c; cyclohexylallene, 2d; t-butylallene) was carried out by [(pi-allyl)NiOCOCF3](2) (1). The polymerization was found to proceed through a living process without any side reactions to yield soluble polymers in high yields, where the resulting polymers had predictable molecular weights and narrow molecular weight distributions. The coordination polymerization of dialkylallene (2e; 3-methyl-1,2-nonadiene, 2f; 2,3-nonadiene) was also carried out to obtain soluble polymers, although the polymerization rate of 2f was found to be considerably low compared with those of monoalkylallenes. (C) 1997 Elsevier Science Ltd.