Co(II)-Catalyzed Additive-Free Transfer Hydrogenation of N-Heteroarenes at Room Temperature

Traditional catalyst development relies on multistep synthesis and isolation of ligand and precatalyst. Designing a catalytic system that can be assembled in situ from easily accessible starting materials can decrease the reaction complexity and enhance the synthetic utility. Herein, we report an inexpensive and commercially available CoBr2·H2O/terpyridine-catalyzed effective and straightforward transfer hydrogenation (TH) protocol for N-heteroarenes, utilizing NH3·BH3 (AB) under ambient conditions. Synthesis of diverse substrates and bioactive molecules demonstrated a practical applicability. Control experiments and DFT studies elucidate the mechanism.