Metal‐Ligand Cooperative Cobalt (II) Catalysts for Synthesis of Triaryl Pyrazolines and Bis(indolyl)methanes via Alcohol Dehydrogenation

In this study, the catalytic activity of cobalt complexes (Cat‐1 and Cat‐2) based on tetrazine ligand was examined for the synthesis of 1,3,5‐triaryl‐substituted 2‐pyrazolines via a multicomponent strategy and the coupling of alcohols with indoles to produce bis(indolyl)methanes (BIMs). The method utilizes alcohols as green alkylating agents under dehydrogenative conditions, offering a sustainable and atom‐economical approach. The methodology exhibits a wide substrate scope of 82 examples showing excellent functional group tolerance, including 13 bioactive compounds. Control experiments studies combined with the detection of key intermediates through UV–vis, fourier‐transform infrared spectroscopy, and high resolution mass spectrometry (HRMS) suggested the involvement of metal‐ligand cooperation in the plausible reaction pathway.