Catalytic cyclopropanation of polybutadienes

Abstract

Abstract Catalytic cyclopropanation of commercial 1,2‐ or 1,4‐ cis ‐polybutadiene, respectively, with ethyl diazoacetate catalyzed by [Tp Br3 Cu(NCMe)] (Tp Br3 = hydrotris(3,4,5‐tribromo‐1‐pyrazolyl)borate) at room temperature afforded high molecular weight ( M n > 10 5 mol −1 ) side‐chain or main‐chain, respectively, carboxyethyl cyclopropyl‐substituted polymers with variable and controlled degrees of functionalization. Complete functionalization of 1,4‐ cis ‐polybutadiene afforded poly[ethylene‐alt‐(3‐ethoxycarbonyl‐cyclopropene)]. Catalytic hydrogenation of residual double bonds of partially cyclopropanated polybutadienes provided access to the corresponding saturated polyolefins. Thermal properties are reported. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010