Visible Light‐promoted C(sp3)‐H α‐Carbamoylation of Cyclic Ethers with Isocyanides.

A protocol exploiting isocyanides as carbamoylating agents for the α‐C(sp3)‐H functionalization of cyclic ethers has been optimized via a combined visible light‐driven hydrogen atom transfer/Lewis acid‐catalyzed approach. The isocyanide substrate scope revealed an exquisite functional group compatibility (18 examples, with yields up to 99 %). Both radical and polar trapping, kinetic isotopic effect and real‐time NMR studies support the mechanistic hypothesis and provide insightful details for the design of new chemical processes involving the generation of oxocarbenium ions. [ABSTRACT FROM AUTHOR]