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

Abstract

A new sustainable catalytic reaction, the synthesis of 1H‐ perimidines from a dinitroarene and an aldehyde in the presence of H2, 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.

Confinement of Cobalt Species in Mesoporous N-Doped Carbons and the Impact on Nitroarene Hydrogenation

“…Figure shows that the solvent strongly influences the catalytic performance, as the use of more polar solvents considerably enhances the conversion compared to nonpolar or low-polar solvents. Following some previous reports, this might be related to hydrogen solubility. ,, …”

Chemoselective Hydrogenation of Olefins Using a Nanostructured Nickel Catalyst

“…The novel Ni/C catalyst was synthesized in a practical two‐step procedure according to the synthesis concept for 3d metal catalysts developed by us [10d–g] (Figure 1): Firstly, the commercially available carbon support (Norit CA1) was wet impregnated with the novel Ni‐salen(prop)(di‐ tert ‐butyl) complex in tetrahydrofuran and the solvent was removed (see Supporting Information for crystallographic data and complex characterization). This was followed by a pyrolysis step at 700 °C in nitrogen atmosphere and a reduction step at 550 °C in forming gas (90/10, N 2 /H 2 ).…”

“…Most of the known and industry-relevant catalyst systems are based on the expensive noble metals ruthenium, rhodium, palladium, platinum and iridium or on difficult to handle and pyrophoric Raney nickel. [8,9] In recent years, hydrogenation with nanostructured 3d metal catalysts step into the focus for many applications as introduced by us [10] and the Beller group. [11] Also, the selective olefin hydrogenation of α,β-unsaturated carbonyls, internal and terminal unsaturated hydrocarbons was addressed with heterogeneous iron [12] , cobalt [13] und nickel [14] catalysts.…”

“…The Ni/C catalyst is easy‐to‐synthesize in a two‐step procedure starting from inexpensive charcoal as support material. By controlled decomposition of a Ni‐salen complex precursor, catalytically active Ni nanoparticles are generated and at the same time stabilized in a nitrogen‐doped carbon matrix on the support [10d–g,11f] …”

Recent Advances in the Synthesis of Perimidines and their Applications

“…Schwob and colleagues [ 92 ] described a novel cobalt-catalyzed reductive cyclization of dinitroarene with aldehydes for the synthesis of 1 H -perimidines with high efficiency, chemoselectivity, and high functional group tolerance. Here, dinitroarene and aliphatic and benzylic aldehydes reacted in the presence of earth copious metal catalyst cobalt and charcoal complex at 6.0 MPa hydrogen pressure, 130 °C temperature in toluene for 20 h to produce 1- H -perimidines in excellent yields.…”