Triphasic Hydroxysilylation of Alkenes by Mechanically Piezoelectric Catalysis

Abstract The 1,2‐hydroxysilylation of alkenes is crucial for synthesizing organosilicon compounds which are key intermediates in material science, pharmaceuticals, and organic synthesis. The development of strategies employing hydrogen atom transfer pathways is currently hindered by the existence of various competing reactions. Herein, we reported a novel mechanochemical strategy for the triphasic 1,2‐hydroxysilylation of alkenes through a single‐electron‐transfer pathway. Our approach not only circumvents competitive reactions to enable the first‐ever 1,2‐hydroxysilylation of unactivated alkenes but also pioneers the research in mechanic force‐induced triphasic reactions under ambient conditions. This gentle method offers excellent compatibility with various functional groups, operates under simple and solvent‐free conditions, ensures rapid reaction time. Preliminary mechanistic investigations suggest that silylboronate can be transformed to a silicon radical by highly polarized Li 2 TiO 3 particles and oxygen under ball‐milling condition.