Mechanism-Inspired Synthesis of Poly(alkyl malonates) via Alternating Copolymerization of Epoxides and Meldrum's Acid
Sarah M Severson1, Bai-Hao Ren1, May Cayzer1
1Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301, United States.
Abstract:
Direct incorporation of malonate units into polymer backbones is a synthetic challenge. Herein, we report the alternating and controlled anionic copolymerization of epoxides and Meldrum's acid (MA) derivatives to access poly(alkyl malonates) using (N,N'-bis(salicylidene)phenylenediamine)AlCl and a tris(dialkylamino)cyclopropenium chloride cocatalyst. This unique copolymerization yields a malonate-containing repeat unit while releasing a small molecule upon MA-derivative ring-opening. Mechanistic and computational studies reveal that the nature of the small molecule released influences overall polymerization kinetics, side reaction behavior, and molecular weight control. Controlled copolymerization of MA derivatives with a range of epoxides ultimately yields a library of new poly(alkyl malonates) with diverse and tunable thermal properties.
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