Oxydiazomethylation of Alkenes via Photoredox Catalysis

Abstract

α‐Diazoesters belong to significantly important carbenoid precursors in synthetic chemistry. Diazomethylation‐based difunctionalization of alkenes is highly valuable but remain nontrivial. Herein, we reported a general and modular approach for the direct 1,2‐oxydiazomethylation of alkenes through visible‐light photoredox catalysis. This process exploits photocatalyzed strategy to convert alkenes to γ‐formyloxyl‐α‐diazoesters using α‐diazo iodonium salts as carbyne precursors, featuring wide substrate tolerance and broad late‐stage diversifications. Mechanistic studies suggest that the formation of γ‐carbocation‐tethered α‐diazoesters plays a crucial role in trapping DMF and H2O to allow for this transformation.