Oxidation/ MCR domino protocol for direct transformation of methyl benzene, alcohol, and nitro compounds to the corresponding tetrazole using a three-functional redox catalytic system bearing TEMPO/Co(III)-porphyrin/ Ni(II) complex

A new general three-functional redox catalytic system has been reported for direct transformation of alcohol, methyl benzene, and nitro compounds to the corresponding 5-substituted 1H-tetrazole and 1-substituted-1H-1,2,3,4-tetrazoles. [Display omitted] •A novel redox catalytic system has developed for oxidation/reduction reactions.•Selective oxidation of alcohols was performed under air conditions.•Direct transformation of nitro and alcohol to the tetrazole derivatives was selectively performed.•The designed catalyst possesses three functionality including Co, Ni, TEMPO centers.•Synergistic effect between Co and Ni controls the efficiency and selectivity of the reactions. A redox catalytic system for oxidation-reduction reactions and the domino preparation of tetrazole compounds from nitro and alcohol precursors was designed, prepared and characterized by UV–vis, GPC, TGA, XRD, EDX, XPS, VSM, FE-SEM, TEM, DLS, BET, NMR, and ICP analyses. The catalyst was prepared via several successive steps by demetalation of chlorophyll b, copolymerization with acrylated TEMPO monomers, complexation with Ni and Co metals (In two different steps), then immobilized on magnetic nanoparticles. The presence of three functional groups including TEMPO, coordinated cobalt, and coordinated nickel in the catalyst, allowed the oxidation of various types of alcohols, alkyl benzenes as well as the reduction of nitro compounds by a single catalyst. All reactions yielded up to 97 % selectivity for oxidation and reduction reactions. Next, the ability of the catalyst to successfully convert alcohol, methyl benzenes and nitro to their corresponding tetrazoles was studied.