Photoinduced 1,2-Hydro(cyanomethylation) of Alkenes with a Cyanomethylphosphonium Ylide

Abstract

An efficient method has been developed for the 1,2-hydro(cyanomethylation) of alkenes, in which a cyanomethyl radical species is generated from a cyanomethylphosphonium ylide by irradiation with visible light in the presence of an iridium complex, a thiol, and ascorbic acid. The cyanomethyl radical species then adds across the C=C double bond of an alkene to form an elongated alkyl radical species that accepts a hydrogen atom from the thiol to produce an elongated aliphatic nitrile. The ascorbic acid acts as the reductant to complete the catalytic cycle.

Charge transfer complex enabled photoreduction of Wittig phosphonium salts

“…1B). 5 Recent advances have been made in transforming alkenes into elongated aliphatic esters with phosphorus ylides using photoredox catalysis by the research groups of Miura, Murakami, 6 Liu 7 and Xiao. 8 In this context, hydro[(alkoxycarbonyl)methylation] reactions of heteroarenes have also been realized by Miura, Murakami and co-workers (Fig.…”

Visible-light-driven 1,2-hydro(cyanomethylation) of alkenes with chloroacetonitrile

“…Recently we reported that the 1,2-hydro(cyanomethylation) of alkenes with phosphonium ylides produces one-carbon-extended nitriles. 2,3 The phosphonium ylide acts as a precursor of a cyanomethyl radical in the presence of a photoredox catalyst under irradiation of visible light. 4 Then, with the intention of shortening the reaction process, we envisaged that haloacetonitriles, the precursor compounds of phosphonium ylides, 5 can be used as a radical source in the 1,2-hydro(cyanomethylation) of alkenes.…”