Functional-group translocation of cyano groups by reversible C–H sampling

Chemical transformations that introduce, remove or manipulate functional groups are ubiquitous in synthetic chemistry 1 . Unlike conventional functional-group interconversion reactions that swap one functionality for another, transformations that alter solely the location of functional groups are far less explored. Here, by photocatalytic, reversible C–H sampling, we report a functional-group translocation reaction of cyano (CN) groups in common nitriles, allowing for the direct positional exchange between a CN group and an unactivated C−H bond. The reaction shows high fidelity for 1,4-CN translocation, frequently contrary to inherent site selectivity in conventional C−H functionalizations. We also report the direct transannular CN translocation of cyclic systems, providing access to valuable structures that are non-trivial to obtain by other methods. Making use of the synthetic versatility of CN and a key CN translocation step, we showcase concise syntheses of building blocks of bioactive molecules. Furthermore, the combination of C–H cyanation and CN translocation allows access to unconventional C–H derivatives. Overall, the reported reaction represents a way to achieve site-selective C–H transformation reactions without requiring a site-selective C–H cleavage step.