Development of Highly Active and Regioselective Catalysts for the Copolymerization of Epoxides with Cyclic Anhydrides: An Unanticipated Effect of Electronic Variation

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• 作者：Angela M. DiCiccio ; Julie M. Longo ; Gabriel G. Rodríguez-Calero ; Geoffrey W. Coates
• 刊名：Journal of the American Chemical Society
• 出版年：2016
• 出版时间：June 8, 2016
• 年：2016
• 卷：138
• 期：22
• 页码：7107-7113
• 全文大小：510K
• 年卷期：0
• ISSN：1520-5126

文摘

Recent developments in polyester synthesis have established several systems based on zinc, chromium, cobalt, and aluminum catalysts for the ring-opening alternating copolymerization of epoxides with cyclic anhydrides. However, to date, regioselective processes for this copolymerization have remained relatively unexplored. Herein we report the development of a highly active, regioselective system for the copolymerization of a variety of terminal epoxides and cyclic anhydrides. Unexpectedly, electron withdrawing substituents on the salen framework resulted in a more redox stable Co(III) species and longer catalyst lifetime. Using enantiopure propylene oxide, we synthesized semicrystalline polyesters via the copolymerization of a range of epoxide/anhydride monomer pairs.