C−C Coupling of Aryl Chlorides and Reduction of Nitroarenes to Amines Employing Recyclable Heterogeneous Green Catalysts

Abstract

AbstractTwo new isostructural inorganic coordination polymers, [M(C14H8O6)(C10H8N2)2H2O)] ⋅ (C3H7NO), (M=Co, Ni) were prepared employing 2, 5‐bis(prop‐2‐yn‐1‐yloxy)terephthalic acid (2,5 BPTA) and 4,4′ bipyridine as ligands. The connectivity between the metal‐centers and the ligands give rise to a two‐dimensional layer structure. The Ni‐containing one has higher stability compared to the Co‐containing one. The Co‐containing compound, 1, was heated in Ar‐atmosphere to prepare Co‐nanoparticles, supported over graphitic carbon. The Co@C−T compounds were found to be active for the Bechamp reaction of reduction of nitroarenes to aminoarenes under solvent‐free condition with good yields and recyclability. The Ni‐containing compound, 2 was loaded with Pd‐nanoparticles by known procedures. The Pd@2 samples were found to be a good catalyst for the Suzuki‐Miyaura C−C coupling of chloroarenes in ethanol at 75 °C in good yield. The present work demonstrates a clean approach for the preparation of new heterogeneous catalysts for the reduction of nitroarenes and especially towards activating chloro‐arenes under recyclable reaction conditions. These catalysts and the reactions are green as the Bechamp reaction employing the Co@C−T catalysts was carried out under solvent‐free conditions and the Pd@2 catalysis employing environmentally benign ethanol.