Microwave-Assisted Cross-Coupling of Nitroarenes with Aryl Boronic Acids

A molybdenum-catalyzed approach for intermolecular C-N coupling that produces aryl- and heteroaryl amines has been developed under microwave irradiation. The formation of C-N bonds with boronic acids and nitroaromatics using readily available catalysts remains a challenge. The method we developed employs a combination of readily available sodium molybdate dihydrate as a catalyst and tri-n-butyl phosphine as an inexpensive reductant to achieve reductive intermolecular coupling of nitroarenes with boronic acids. This approach has shown its versatility in facilitating the formation of Csp2-N bonds from aryl-boronic acids as well as Csp3-N bonds from alkyl-boronic acids. In addition, this reaction shows stereospecificity when Csp3-N bonds are formed. An array of boronic acids underwent C-N coupling with nitro arene providing the desired products in good yields The synthesis of aromatic amines has implications in a wide range of chemical applications. Here we described a microwave-assisted method for the synthesis of diarylamines in the presence of readily available sodium molybdate dihydrate as a catalyst. image