Organic Photoredox-Catalyzed Silyl Radical Generation from Silylboronate

A visible-light-driven silyl radical generation method from silylboronates has been developed. The activation of silylboronates with a catalytic amount of mild base promoted the single-electron oxidation process to form silyl radicals. Facile single electron transfer for the borate form readily occurred without hydrogen atom transfer for hydrosilane in the presence of various photoredox catalysts. Combining this protocol with radical-mediated N-heterocyclic carbene catalysis enabled the acylsilylation of alkenes via a radical relay process with silyl radical generation. Furthermore, the recent advanced methods for the synthesis of silylboronates significantly improved the utility of this silyl radical generation process.