Exploiting Transient Radical Cations as Brønsted Acids for Allylic C-H Heteroarylation of Enol Silyl Ethers.

Intermediary radical cations, generated through single-electron oxidation of enol silyl ethers by excited Ir-based photocatalysts, can be exploited as Brønsted acids for the activation of heteroarylcyanides. This strategy enables the direct allylic C-H heteroarylation of enol silyl ethers under visible-light irradiation.