Highly Active and Selective Photocatalytic Oxidation of Organosilanes to Silanols

Silanols are ubiquitous building blocks for organic synthesis and material fabrication. To date, a number of stoichiometric and catalytic methods have been developed for the direct oxidation of Si-H to Si-OH bonds. A common challenge in the oxidation of silanes is to combine both catalytic activity and selectivity. Herein, we report a highly active and selective photocatalytic approach for the oxidation of organosilanes to silanols. Using plasmonic Au-TiO₂as a photocatalyst for dimethylphenylsilane oxidation enables complete conversion (>99% yield) and high selectivity (98.3%) with catalytic activity up to 121.8 g g^-1. The observed activity substantially exceeds those of most reported homogeneous and heterogeneous catalysts. Silanol synthesis could be achieved under mild conditions in either aqueous or solvent-free conditions and allows the oxidation of a broad scope of sterically hindered hydrosilanes in excellent yield and selectivity. The general concept of photocatalytic synthesis of valuable silanols is further demonstrated by five photocatalysts.