LIVING CYCLOPOLYMERIZATION OF DIETHYL DIPROPARGYLMALONATE BY MO(CH-T-BU)(NAR)[OCME(CF3)2]2 IN DIMETHOXYETHANE

Cyclopolymerization of diethyl dipropargylmalonate (1) by Mo(CH-t-Bu)(NAr)[OCMe(CF3)2]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)n polymers have low polydispersities (M(w)/M(n) less-than-or-equal-to 1.25) and values for M(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).