A Cobalt Catalyst Permits the Direct Hydrogenative Synthesis of 1 H ‐Perimidines from a Dinitroarene and an Aldehyde

A new sustainable catalytic reaction, the synthesis of 1 H ‐ perimidines from a dinitroarene and an aldehyde in the presence of H 2 , was achieved. An earth‐abundant metal catalyst was developed to permit the efficient, highly chemoselective, and consecutive hydrogenation of dinitroarenes. The catalyst was reusable and easy to handle. The use of a specific Co complex and its pyrolysis at a certain temperature was crucial to achieve high activity for the complex organic transformation. Benzylic and aliphatic aldehydes could undergo the hydrogenative condensation, and many functional groups, including hydrogenation‐sensitive examples such as iodo aryl, nitrile, olefin, and alkyne groups, were tolerated.