Metal Catalysed Deoxygenation Reactions by Carbon Monoxide of Nitroso and Nitro Compounds

Abstract

In recent years the catalytic carbpnylation of aromatic nitro compounds, ArNO2, has become a very intense field of research. This is due to the fact that a series of industrially important compounds can be obtained from nitro compounds and carbon monoxide in a single step. Probable intermediates in these carbonylation reactions are the corresponding nitroso compounds, ArNO. The interaction of nitroso and nitro compounds with the metal centre has been reviewed and their metal-assisted stoichiometric reactions have been discussed. Their catalytic reactions, with particular emphasis on nitro compounds as substrates, have also been reviewed. Different sections have been thus-devoted to the synthesis of: amines, azo derivatives, Schiff bases, heterocycles (pyridines, quinolines and indoles), isocyanates, carbamates, ureas, N-substituted amides and imides. Some reactions involving aliphatic nitro compounds have also been considered. Particular attention has been paid to the catalytic reactions leading to isocyanates and carbamates, being these derivatives important final products and/or intermediates in the synthesis of pesticides and polyurethanes. The action of homogeneous, and of heterogeneous catalysts as well, has been discussed.