Ir-Catalyzed Selective Reductive N-Formylation and Transfer Hydrogenation of N-Heteroarenes

Selective functionalization has numerous potential applications in the modification of bioactive compounds and pharmaceuticals. Herein, we advance a new approach for the selective reductive N-formylation of N-heteroarenes and transfer hydrogenation using Ir^III complexes as catalysts. The combination of solvent, equivalent of formic acid (FA), reaction temperature, and iridium catalyst exerts high product selectivity, delivering divergent selective formations of reductive N-formylation and transfer hydrogenation products in excellent yields. In this process, FA can be employed as not only the hydrogen source but also the reductive N-formylation reagent under different reaction conditions.