B(C6F5)3-Catalyzed Group Transfer Polymerization of Acrylates Using Hydrosilane: Polymerization Mechanism, Applicable Monomers, and Synthesis of Well-Defined Acrylate Polymers

Abstract

We demonstrated the B(C6F5)3-catalyzed group transfer polymerization (GTP) of acrylate monomers with hydrosilane by the in situ formation of silyl ketene acetals (SKAs) as the initiator by the B(C6F5)3-catalyzed 1,4-hydrosilylation of acrylate monomers and hydrosilane. In addition, this new GTP method was clarified in terms of the polymerization mechanism, scope and limitation of the acrylate monomers, the livingness of the polymerization, and the synthesis of statistic and block acrylate copolymers and ω-end-functionalized acrylate polymers. A mechanism involving six elementary reactions was proposed based on the specified analysis of the 1,4-hydrosilylation reaction and the usual GTP using a Lewis acid catalyst. The B(C6F5)3-catalyzed GTP using Me2PhSiH was applicable for not only various alkyl acrylates, such as the methyl, 2-ethylhexyl, cyclohexyl, and dicyclopentanyl acrylates, but also functional acrylates, such as the 2-methoxyethyl, 2-(2-ethoxyethoxy)ethyl, tetrahydrofurfuryl, allyl, triisopropyls...