Living cyclopolymerization of diethyl dipropargylmalonate by Mo(CH-t-Bu)(NAr)[OCMe(CF3)2]2 in dimethoxyethane

Abstract

Cyclopolymerization of diethyl dipropargylmalonate (1) by Mo(CH-t-Bu)(NAr)[OCMe(CF{sub 3}){sub 2}]{sub 2} (2) in dimethoxyethane (DME) proceeds in a living manner to give a conjugated polyene that contains both five- and six-membered rings incorporated into the polyene backbone. Cyclization to give the five-membered ring is believed to prevent deactivation of the catalyst. GPC analysis shows that poly(1){sub n} polymers have low polydispersities (M{sub w}/M{sub n} {le} 1.25) and values for M{sub n} that increase linearly with the amount of monomer employed. The living nature of the polymerization was also demonstrated by synthesis of a block copolymer from 20 equiv of 1 followed by 200 equiv of 2,3-dicarbomethoxynorbornadiene (5). 28 refs., 1 fig., 1 tab.