Palladium-Mediated Polymerization of Alkyl Diazoacetates To Afford Poly(alkoxycarbonylmethylene)s. First Synthesis of Polymethylenes Bearing Polar Substituents

Polymerization of alkyl diazoacetates [N2CHCO2R: R = Et (1a) and Me (1b)] mediated by PdCl2 in the presence of an amine gave poly(alkoxycarbonylmethylene)s [(CHCO2R)n: R = Et (2a,b), Me (3a,b)] bearing an ester group on every carbon atom of their main chains. MALDI−TOF−MS analyses of the polymers 2a and 3b indicated that the degree of polymerization of the polymers extended up to nearly 100. The Pd-mediated polymerization of 1a and 1b in the presence of pyridine afforded the polymers quantitatively after reprecipitation from CHCl3 into n-hexane. A mechanism of the polymerization initiated with a Pd-assisted nucleophilic attack of an amine to the monomers is proposed.