An Easy Route to N , N ‐Diarylhydrazines by Cu‐Catalyzed Arylation of Pyridine‐2‐carbaldehyde Hydrazones with Aryl Halides

A copper‐catalyzed C–N coupling reaction is described for the preparation of pyridine‐2‐carbaldehyde N , N ‐diarylhydrazones by the arylation of N ‐mono‐ or ‐non‐substituted hydrazones with aryl bromides/iodides, and the subsequent conversion of the hydrazones into N , N ‐diarylhydrazines by a transimination process with an aqueous solution of H 2 NNH 2 . The reaction features the use of CuI as the catalyst without the need for external ligands. This methodology provides a convenient alternative to the synthesis of structurally diverse N , N ‐diarylhydrazines from simple, easily accessible precursors.