Rongalite as a Methylene Surrogate: Synthesis of Heterodiarylmethanes via C(sp2)-H Functionalization

An efficient method for the synthesis of heterodiarylmethanes through the coupling of imidazo1, 2- a pyridines and heteroarenes using indoles employing rongalite as a methylenating reagent has been developed. This regioselective C–H functionalization provides a wide range of heterodiarylmethanes of imidazo1, 2- a pyridines and imidazo2, 1- b thiazole. Here, rongalite plays a crucial role in generating a C1 unit in situ, which triggers the heterodiarylmethylation process. The use of inexpensive rongalite (ca. 0. 03/1 g), mild reaction conditions, and gram-scale synthesis are some of the key features of this methodology.