Molecular Catalysis
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
a,
b,
c
Boshra Mahmoudi , Amin Rostami *, Milad Kazemnejadi *, Baram Ahmed Hamah-Ameen
a
Chemistry Department, College of Science, University of Kurdistan, Pasdaran Street, 66177-15177, Sanandaj, Iran
b
Department of Chemistry, College of Science, University of Birjand, Birjand, P.O. Box 97175-615, Iran
c
Chemistry Department, College of Science, University of Sulaimani, Kurdistan Region, Iraq
A R T I C L E I N F O
A B S T R A C T
Keywords:
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.
Domino reaction
Selective oxidation
Selective reduction
Redox catalyst
Multifunctional
Demetalated chlorophyll
Introduction
Fe/TRGO [4], (4) Fe
6], and (6) CuFe
interesting paper used human hair in the presence of NaBH
3
O
4
-MWCNTs@PEI-Ag [5], (5) Zn powder/ CuSO
4
[
2
O
4
/ NaBH
4
[10]. Recently, Gholinejad et al., in an
Oxidation/ reduction reactions have a special place and are widely
used in organic chemistry [1,2]. The products of oxidation and reduction
reactions are useful and practical precursors in the synthesis of organic
compounds, especially multicomponent reactions (MCRs) [3]; one of
these reactions is the preparation of tetrazol derivatives.
4
for selective
reduction of nitro to amine [7]. Very recently, Nasrollahzadeh and his
co-workers reviewed the recent methodologies in graphene-based pho-
tocatalysts for the nitro reduction [8].
On the other hand, carbonyl compounds are among the most widely
used compounds in organic synthesis, preparation of pharmaceutical,
agriculture compounds, etc., and its direct preparation through oxida-
tion of alcohols, is the simplest and most cost-effective method [2,11].
The 5-substituted 1H-tetrazoles and 1-substituted-1H-1,2,3,4-tetra-
zoles are two main groups of tetrazols, and cyclization between a sus-
ceptible compound such as amine or nitrile in the presence of azide ion is
the most common method of the preparation of these compounds [4,
12–14]. Mittal and Awasthi studied recent advances in the preparation
of 5-substituted 1H-teratazoles in a review paper [3]. Tetrazols have a
special place in medicine and pharmacy and have properties such as
antibacterial, antifungal, antibiotic, anti-HIV, antihypertensive, anti-
convulsant agents, anti-inflammatory, etc. [15–17]. Sartans are a large
Aromatic amines are one of the most important and practical raw
materials and intermediates in organic synthesis, because they are
widely used in the preparation of chemicals required in pharmaceuti-
cals, dyes, agriculture, biological compounds, rubber, photography,
synthetic resins, and other industries [4–6]. In addition, in organic
synthesis, amines are widely used in the preparation of azo compounds,
isocyanates, amides, imines, and diazonium salts [7,8]. Reduction of
nitro compounds, as one of the most effective and available precursors,
is one of the most common and popular method for the preparation of
amines [4]. A variety of catalytic systems, along with various reducing
agents, have been reported for reduction of nitro to amine (recent re-
2 2 3 4
ports): (1) Ni BH [1], (2) Ag-rGO/g-C N / visible light [9], (3)
*
Received 23 August 2020; Received in revised form 11 November 2020; Accepted 17 November 2020
2
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