Copper‐catalyzed C−H Selenation of 2‐Substituted Benzo[b]furans with Diaryl Diselenides: Synthesis of 2‐Substituted 3‐Selanylbenzo[b]furan Derivatives

Organoselenium compounds are potentially active substances. Herein, a novel method for the synthesis of 2‐substituted 3‐selanylbenzo[b]furans that uses Cu‐catalyzed C−H selenation, an efficient method for chemically transforming aromatic heterocycles, is described. The reactions of 2‐substituted benzo[b]furans with diaryl diselenides in the presence of 10 mol% copper iodide (CuI) at 120 °C in dimethyl sulfoxide (DMSO) afforded the corresponding 2‐substituted 3‐selanylbenzo[b]furans in moderate‐to‐excellent yields. The reaction proceeds efficiently and both of the two selanyl groups of the diselenide are transferred to the coupling products.