Organopotassium‐Catalyzed Silylation of Benzylic C(sp3)−H Bonds

Abstract

AbstractBenzylsilanes have found increasing applications in organic synthesis as bench‐stable synthetic intermediates, yet are mostly produced by stoichiometric procedures. Catalytic alternatives based on the atom‐economical silylation of benzylic C(sp3)−H bonds remain scarcely available as specialized directing groups and catalytic systems are needed to outcompete the kinetically‐favored silylation of C(sp2)−H bonds. Herein, we describe the first general and catalytic‐in‐metal undirected silylation of benzylic C(sp3)−H bonds under ambient, transition metal‐free conditions using stable tert‐butyl‐substituted silyldiazenes (tBu−N=N−SiR3) as silicon source. The high activity and selectivity of the catalytic system, exemplified by the preparation of various mono‐ or gem‐bis benzyl(di)silanes, originates from the facile generation of organopotassium reagents, including tert‐butylpotassium.