Photocatalytic site-selective radical C(sp3)–H aminoalkylation, alkylation and arylation of silanes

Organosilicon compounds are of great value in chemistry and material science. However, site-selective C–H bond functionalization of simple silanes to prepare more complex organosilicon compounds is challenging because of the presence of multiple C–H bonds in the same molecule. Here we report a broadly applicable photocatalytic site-selective radical functionalization of organosilicon compounds enabled by the β-silicon effect, wherein a silyl group selectively activates β-C(sp3)–H bonds, leading to lower bond dissociation energy than that of α-C(sp3)–H bonds and γ-C(sp3)–H bonds. Various β-C(sp3)–H bond aminoalkylation, alkylation and arylation reactions have been achieved and applied in complex molecule synthesis. Site-selective C–H functionalization of silanes is challenging because of the presence of multiple C–H bonds in the same molecule. Now a general photocatalytic site-selective radical functionalization of organosilicon compounds is reported, enabled by the β-silicon effect, which activates β-C(sp3)–H bonds. These reactions are applicable to linear and complex cyclic silanes.