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The alternating copolymerization of functional alkenes, CH2CH(CH2) x OH (x = 2, 3, 4, 9), CH2CH(CH2) x COOH (x = 1, 2, 4, 8), and 4-allylanisole, with carbon monoxide was achieved by using [Pd(Me-DUPHOS)(MeCN)2](BF4)2 [Me-DUPHOS = 1,2-bis(2,5-dimethylphospholano)benzene] as the catalyst. The resultant polymers were optically active with isotactic sequences in the backbone. With most alkenes, the polymers had poly(1,4-ketone) and/or “regular” poly(spiroketal) (i.e., 1,6-dioxaspiro[4.4]nonane) enchainments. However, with 4-penten-1-ol and 3-buten-1-ol, the participation of the pendant hydroxyl group in intrachain reactions led to the formation of unusual polycyclic repeating units in the backbone. A comparison of [Pd(Me-DUPHOS)(MeCN)2](BF4)2 with [Pd(DPPP)(MeCN)2](BF4)2 [DPPP = 1,3-bis(diphenylphosphino)propane] indicated that the former was a significantly better catalyst for the alternating copolymerization of alkenols and alkenoic acids with carbon monoxide.

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The alternating copolymerization of 3,3-dimethylallene with carbon monoxide was achieved using [Pd(PPh3)2(MeCN)2](BF4)2 as the catalyst. The use of bidentate phosphines resulted in drastically reduced yields. In order to gain insight into the copolymerization mechanism, the stepwise successive insertions of 3,3-dimethylallene and carbon monoxide into palladium−carbon bonds in the complexes, Pd(PPh3)2(Me)(Cl), [Pd(PPh3)2(C(O)-C6H4-Me-p)(MeCN)](BF4), and [Pd[(Dppp)(Me)(MeCN)](BF4) (Dppp:  1,3-bis(diphenylphosphino)propane), were studied. These studies, in turn, led to a novel living catalytic system which was used to synthesize a terpolymer with alt-allene-carbon monoxide and alt-ethene-carbon monoxide blocks.

Bisbenzimidazole copper dichloride complexes (CuBBIMs), when activated with methylaluminoxane, catalyze the random copolymerization of ethylene with acrylates to produce highly linear functional copolymers. To probe the sensitivity of the copolymerization to the catalyst structure, a series of CuBBIM catalysts with various steric, electronic, and geometric ligand characteristics was prepared, including CuBBIMs having benzimidazole ring substituents and ligand backbones of various lengths. Four different acrylates were also evaluated as comonomers (t‐butyl acrylate, methyl acrylate, t‐butyl methacrylate, and methyl methacrylate). Although no obvious ligand‐based influences on copolymerization were identified, the structure of the acrylate comonomer was found to exert significant effects. Copolymers prepared with t‐butyl methacrylate comonomer exhibited the highest ethylene contents (31–63%), whereas those prepared with methyl acrylate contained only minor amounts of ethylene (<15%). Copolymerizations carried out at lowered acrylate feed levels generally had increased ethylene contents but showed smaller yields, lowered molecular weights, and increased branching. Unusual ketoester structures were also observed in the methyl acrylate and methyl methacrylate containing copolymers, suggesting that the acrylate ester group size may be an important controlling factor for copolymerization. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1817–1840, 2006