Controlled Cyclopolymerization of Dienes by Late Transition Metal Complexes

Abstract

This article reviews our recent studies on cyclopolymerization of 1, 6-heptadiene derivatives catalyzed by late transition metal complexes. Pd-diimine complexes initiate cyclopolymerization of the 1, 6-heptadienes with functional groups to afford the polymers containing functionalized trans-l, 2-disubstituted cyclopentane rings along the polymer chain. Copolymerization of the dienes with ethylene and α-olefins also causes quantitative cyclization of the diene during the polymer growth. 1, 6-Octadiene and higher mono-terminal dienes undergo the cyclopolymerization accompanied by chain walking of the growing polymer, leading to the polymers with trans-l, 2-disubstituted cyclopentane groups located regularly along the linear polymer chain. The Fe and Co complexes with a bis(imino)pyridine ligand promote the polymerization of unsubstituted 1, 6-heptadiene with quantitative cyclization to yield the polymers containing five-membered rings. The Fe complex-catalyzed reaction affords the polymers composed of cis-fused five-membered rings, whereas the polymer obtained by using Co catalyst contains trans-fused rings selectively.