Rhodium-Catalyzed Regioselective Direct C-H Amidation of 2,4-Diarylquinazoline with Sulfonyl Azides: An Example of Steric Hindrance Regulated Mono- and Diamidation Selectivity

An unprecedented steric hindrance controlled regioselective rhodium-catalyzed direct C-H amidation of 2,4-diarylquinazoline was described. Sulfonyl azides were used as the amine source to provide a variety of amide-functionalized 2,4-diarylquinazolines in high efficiency. The reaction proceeded under mild conditions, had good functional group tolerance with a broad scope of substrates, and afforded moderate to good product yields. Excellent monoamidation selectivity was achieved with the assistance of meta substituents.