Block copolymerization of allene derivatives with isocyanides by the coordination polymerization with π-allylnickel catalyst

A living block copolymerization of allene derivatives with 1-phenylethyl isocyanide ( 3 ) using [(allyl)NiOCOCF₃]₂ ( 1 ) is described. After complete polymerization of allene monomers such as n-octyloxyallene ( 2A ) with 1 , further addition of 3 to the reaction system yielded the corresponding block copolymers in high yield. For instance, a block copolymer ( 4A , M_n = 39,600, M_w/M_n = 1.20) was obtained in 96% yield by the addition of 3 ([ 3 ]/[ 1 ] = 250) to the living solution of poly(n-octyloxyallene) (M_n = 14,400, M_w/M_n = 1.03) prepared by the polymerization of 2A in the ratio of [ 2A ]/[ 1 ] = 90. The resulting copolymer was a brownish orange gum or a solid, depending on the length of each of the segments. The solubility of the block copolymers could be controlled by the allene components. The copolymer of 2A with 3 having appropriate length of segments was soluble in n-hexane, while that of methoxyethoxyethoxyallene ( 2D ) with 3 was soluble in methanol. © 1997 John Wiley & Sons, Inc.