Graphene oxide nanosheets supported N-heterocyclic Cu(II) complex for the synthesis of N-benzyl-N-aryl-5-amino-1H-tetrazoles

Tetrazoles, one of the versatile class of N-rich heterocycles, have attracted increasing attention over the past years owing to their exceptional properties (e.g. highest acidity, highest number of N atoms with well-stability, high formation enthalpy, maximum dipole moment, and lowest basicity) and widespread applications (e.g. medicinal, biological, and industrial) [1,2]. They occupied the superior place in severe research activity due to their exceptional properties/features in the pharmaceutical as isosteres/lipophilic spacers, in the coordination chemistry as ligands, and in the material science as rocket propellants/explosives/gas generators [1-3]. In this work, we have reported immobilization of 5-(4-bromophenyl) amino-1H-tetrazole-copper(II) complex on the surface of graphene oxide nanosheets (GONS) as catalyst towards the synthesis of N-benzyl-N-aryl-5-amino-1H-tetrazoles via [2+3] cycloaddition reaction of as-prepared N-benzylarylcyanamides with NaN3. The structural features of nanocatalyst (GONS-Tet-Cu(II)) were investigated by FT/IR, (HR)TEM, FESEM, XRD, TG/DTG, EDS and elemental mapping. FT/IR, 1H, 13C and 15N NMR were used to characterize the synthesized products. Besides, the GONS-Tet-Cu(II) nanocatalyst could be reused up to eight successive cycles.

Keywords:

N-Benzyl-N-aryl-5-amino-1H-tetrazoles , N-benzyl-N-arylcyanamides , GONS-Tet-Cu(II) nanocatalyst