Highly Active Titanocene Catalysts for Epoxide Hydrosilylation: Synthesis, Theory, Kinetics, EPR Spectroscopy

Abstract

A catalytic system for titanocene-catalyzed epoxide hydrosilylation is described. It features a straightforward preparation of titanocene hydrides that leads to a reaction with low catalyst loading, high yields, and high selectivity of radical reduction. The mechanism was studied by a suite of methods, including kinetic studies, EPR spectroscopy, and computational methods. An unusual resting state leads to the observation of an inverse rate order with respect to the epoxide.

Keywords: homogeneous catalysis; hydrogen-atom transfer; hydrosilylation; radicals; titanium.