Cyano group translocation to alkenyl C(sp2)–H site by radical cation catalysis

Abstract

Achieving the direct translocation of a functional group to unactivated C–H sites within a molecule, while maintaining its structural integrity, presents a notable challenge in the realm of organic synthesis. Here, we report that photocatalytic quinuclidine-based radical cation catalysis can enable selective 1,4-cyano translocation to alkenyl C(sp2)–H sites without imparting any extraneous modifications. The approach leverages N-centered radical cations as catalysts to facilitate both radical translocation and ionic elimination, thereby restoring the double bond and enabling positional exchange between a CN group and a C(sp2)–H bond. This results in the formation of alkenyl cyanide, a versatile linchpin that can easily undergo substitution reactions with a wide range of nucleophiles then lead to diverse difunctionalizations of alkenes. Consequently, this CN translocation approach complements the existing state-of-the-art method of radical-induced alkene 1,2-difunctionalization via functional group translocation. The direct relocation of a functional group to unactivated C–H sites, accomplished without imparting any extraneous modifications to the molecule, is a persistent challenge in organic chemistry. Here, the authors present a selective 1,4-cyano translocation to alkenyl C(sp2)–H sites via radical cation catalysis.

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