Copper-catalyzed C-N Bond formation/ C-H Activation of Heteroarenes

The transition-metal-catalyzed selective C-N bond formation reaction of heteroarenes is a highly important transformation in synthetic chemistry since five-membered heterocycles with amine group are widely employed in biological, pharmaceutical, and material sciences [1]. Methods to synthesize this skeleton include cyclocondensation reactions from two functionalized precursors, copper catalyzed Ullmann and Goldberg couplings [2-4]. There is description of successful copper catalyst systems with O2 as oxidant, which can construct the C-N bond of heteroarenes efficiently either by decarboxylative coupling with formamides or by a direct C-H amination protocol with secondary amines under mild reaction conditions [5]. This research involved an efficient, clean and facile synthetic route for C-H amination of substituted heteroarenes with all types of amines using Cu-nanocomposite as eco-friendly nanocatalyst under solvent-free conditions at ambient temperature and affording excellent yields. (Scheme 1).