Gold(I)-Catalyzed Regioselective C≡C Bond Cleavage of o -Alkynyl Anilines with tert -Butyl Nitrite to Prepare 2-Aminobenzonitriles

In this work, a variety of 2-aminobenzonitriles were prepared in moderate to good yields through a gold(I)-catalyzed regioselective C≡C bond cleavage of o-alkynyl anilines with tert-butyl nitrite (TBN). The mechanistic studies revealed that the reaction involved a gold(I)-catalyzed 5-endo-dig cyclization of the o-alkynyl anilines to indoles, TBN-mediated nitrosation of indoles, and gold(I)-catalyzed C–C bond cleavage over three steps. The present method features a broad substrate scope, good functional group compatibility, and efficient and highly regioselective C≡C bond cleavage, with the amino group serving as a directing group and TBN as the nitrogen source of nitriles.