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 IrIII 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.