Palladium-mediated polymerization of diazoketones (1a, 2a, 3a, 4a, and 6a) proceeded to give poly(acylmethylene)s (1b, 2b, 3b, 4b, and 6b), in which all of the main chain carbons had acyl groups. The structures of the novel polymers were characterized by NMR spectroscopy, elemental analyses, and molecular weight measurements (GPC and VPO), where the results of the elemental analyses suggested incorporation of a small amount of azo group (−NN−) into the main chain (ca. one −NN− per polymer chain). The presence of a CC double bond adjacent to the carbonyl carbon in the monomers was required for the polymerization to proceed. Palladium-mediated copolymerizations using a variety of combinations of diazoketones and ethyl diazoacetate, 8, as comonomers proceeded to give various poly(substituted methylene)s.

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.

Phenyldiazomethane was found to be polymerized by the reaction with palladium‐based initiating systems. Homopolymerization of phenyldiazomethane afforded a polymer, whose main chain consists of phenylmethylene framework (–CHPh–) and azo groups (–NN–). The incorporation of the azo group was suggested from the results of elemental analyses, and confirmed by Raman spectroscopy. Palladium‐mediated copolymerization of phenyldiazomethane with (E)‐1‐diazo‐3‐nonen‐2‐one or ethyl diazoacetate proceeded to give copolymers having phenylmethylene framework, azo group, and acylmethylene or ethoxycarbonylmethylene framework in the main chain, with a variety of their compositions. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1536–1545, 2007