Pd-Catalyzed Late-Stage Installation of Nitrile and Carbamoyl Groups via a Cross-Coupling Approach of Thianthrenium Salts with Isonitriles

We report the late-stage C–H functionalization of inert C–H bonds of arenes, heteroarenes, and alkenes for the introduction of nitrile and carbamoyl functionalities via Pd-catalyzed cross-coupling of thianthrenium salts with isonitriles. We have utilized isonitrile as an equivalent to carbene for the precursor of nitrile and carbamoyl functional groups under Pd-catalyzed cross-coupling of in situ generated thianthrenium salts from arenes, heteroarenes, alkenes, and thianthrene sulfoxide. Our thorough mechanistic studies have proven that the reaction proceeded through the Pd^II–carbene complex via cross-coupling after the oxidative addition of thianthrenium salts. We have successfully synthesized a library of nitrile and carbamoyl functionalities containing compounds that include active pharmaceuticals, diversely substituted arenes, heteroarenes, and alkenes by using a Pd-catalyzed cross-coupling approach with isonitrile. Our approach also led to the synthesis of various pharmaceutical active drugs, the interconversion of nitrile and carbamoyl functionalities to other functional groups, and the synthesis of heterocyclic compounds.