A Review on Traditional and Modern Methods for the Synthesis of Aromatic Azo
Compounds

Ashok   Raj   Patel; Geetika      Patel; Arti      Srivastava; Subhash      Banerjee
doi:10.2174/0113852728245448231011103950
Abstract

Aromatic azo compounds are “derivatives of diazene/diimide”, wherein the two hydrogens are substituted by phenyl groups. Azo compounds are very important universal scaffolds that show multiple applications in many areas of science, mainly chemical industries, where they are used in the synthesis of organic dyes, pigments, food additives, indicators, etc. They also remarkably exhibit various potential applications in the fields of pharmaceuticals, electronics, optics, etc., because of their fascinating photophysical properties. Moreover, several azo compounds have been strongly utilized as chemosensors, diagnostic probes, radical initiators, nanotubes, and building blocks of various polymers as well as natural products. This interesting and immense importance of the azo compounds has attracted the attention of researchers to establish novel synthetic routes to synthesize these important scaffolds. In organic chemistry, azo compounds can be synthesized by various methods utilizing coupling reactions with the aid of a catalyst or sometimes in the absence of it. The main purpose of writing this review was to provide a summary of the synthesis of both symmetric and asymmetric azobenzenes via various traditional and recently developed oxidative azo-coupling reactions.
« Previous Next »
Graphical Abstract

[1]
Cruickshank, D.L.; Hendon, C.H.; Verbeek, M.J.R.; Walsh, A.; Wilson, C.C. Polymorphism of the azobenzene dye compound methyl yellow. CrystEngComm,  2016, 18(19), 3456-3461.
 [http://dx.doi.org/10.1039/C6CE00387G]

[2]
Fehrentz, T.; Schönberger, M.; Trauner, D. Optochemical genetics. Angew. Chem. Int. Ed.,  2011, 50(51), 12156-12182.
 [http://dx.doi.org/10.1002/anie.201103236] [PMID: 22109984]

[3]
Hunger, K. In Industrial dyes: Chemistry, properties, applications; Wiley-VCH: Weinheim, Germany, 2003. 

[4]
Banerjee, I.A.; Yu, L.; Matsui, H. Application of host-guest chemistry in nanotube-based device fabrication: photochemically controlled immobilization of azobenzene nanotubes on patterned α-CD monolayer/Au substrates via molecular recognition. J. Am. Chem. Soc.,  2003, 125(32), 9542-9543.
 [http://dx.doi.org/10.1021/ja0344011] [PMID: 12903992]

[5]
Yu, Y.; Nakano, M.; Ikeda, T. Directed bending of a polymer film by light. Nature,  2003, 425(6954), 145.
 [http://dx.doi.org/10.1038/425145a] [PMID: 12968169]

[6]
Cisnetti, F.; Ballardini, R.; Credi, A.; Gandolfi, M.T.; Masiero, S.; Negri, F.; Pieraccini, S.; Spada, G.P. Photochemical and electronic properties of conjugated bis(azo) compounds: An experimental and computational study. Chemistry,  2004, 10(8), 2011-2021.
 [http://dx.doi.org/10.1002/chem.200305590] [PMID: 15079841]

[7]
Venkataramani, S.; Jana, U.; Dommaschk, M.; Sönnichsen, F.D.; Tuczek, F.; Herges, R. Magnetic bistability of molecules in homogeneous solution at room temperature. Science,  2011, 331(6016), 445-448.
 [http://dx.doi.org/10.1126/science.1201180] [PMID: 21273483]

[8]
Szymański, W.; Beierle, J.M.; Kistemaker, H.A.V.; Velema, W.A.; Feringa, B.L. Reversible photocontrol of biological systems by the incorporation of molecular photoswitches. Chem. Rev.,  2013, 113(8), 6114-6178.
 [http://dx.doi.org/10.1021/cr300179f] [PMID: 23614556]

[9]
Wang, Q.; Yi, L.; Liu, L.; Zhou, C.; Xi, Z. A thermostable azo-linker for reversible photoregulation of DNA replication. Tetrahedron Lett.,  2008, 49(34), 5087-5089.
 [http://dx.doi.org/10.1016/j.tetlet.2008.06.027]

[10]
Son, J.Y.; Kim, S.; Jeon, W.H.; Lee, P.H. Synthesis of cinnolin-3(2H)-one derivatives from Rh-catalyzed reaction of azobenzenes with diazotized meldrum’s acid. Org. Lett.,  2015, 17(10), 2518-2521.
 [http://dx.doi.org/10.1021/acs.orglett.5b01052] [PMID: 25932946]

[11]
Lim, S.Y.; Hong, K.H.; Kim, D.I.; Kwon, H.; Kim, H.J. Tunable heptamethine-azo dye conjugate as an NIR fluorescent probe for the selective detection of mitochondrial glutathione over cysteine and homocysteine. J. Am. Chem. Soc.,  2014, 136(19), 7018-7025.
 [http://dx.doi.org/10.1021/ja500962u] [PMID: 24754635]

[12]
Zollinger, H. Color Chemistry: Syntheses, properties and applications of organic dyes and pigments; VCH: NY, 1987. 

[13]
Gordon, P.F.; Gregory, P. Organic Chemistry in Colour; Springer: NY, 1983. 
 [http://dx.doi.org/10.1515/9783112541746]

[14]
Ashutosh, P.N.D.; Mehrotra, J.K. Azo dyes as metallochromic indicators. Colourage,  1979, 26, 25.

[15]
Athey, R.D. Free radical initiator basics. Eur. Coat. J.,  1998, 3, 146-149.

[16]
Sandborn, W.J. Rational selection of oral 5-aminosalicylate formulations and prodrugs for the treatment of ulcerative colitis. Am. J. Gastroenterol.,  2002, 97(12), 2939-2941.
 [http://dx.doi.org/10.1111/j.1572-0241.2002.07092.x] [PMID: 12492172]

[17]
Ikeda, T.; Tsutsumi, O. Optical switching and image storage by means of azobenzene liquid-crystal films. Science,  1995, 268(5219), 1873-1875.
 [http://dx.doi.org/10.1126/science.268.5219.1873] [PMID: 17797528]

[18]
Crano, J.C.; Guglielmetti, R.J. Organic photochromic and thermochromic compounds; Plenum Press: New York, 1999. 

[19]
Feringa, B.L.; van Delden, R.A.; Koumura, N.; Geertsema, E.M. Chiroptical molecular switches. Chem. Rev.,  2000, 100(5), 1789-1816.
 [http://dx.doi.org/10.1021/cr9900228] [PMID: 11777421]

[20]
Murakami, H.; Kawabuchi, A.; Kotoo, K.; Kunitake, M.; Nakashima, N. Nakashima,A light-driven molecular shuttle based on a rotaxane. N. J. Am. Chem. Soc.,  1997, 119(32), 7605-7606.
 [http://dx.doi.org/10.1021/ja971438a]

[21]
Merino, E.; Ribagorda, M. Control over molecular motion using the cis- trans photoisomerization of the azo group. Beilstein J. Org. Chem.,  2012, 8, 1071-1090.
 [http://dx.doi.org/10.3762/bjoc.8.119] [PMID: 23019434]

[22]
García-Amorós, J.; Velasco, D. Recent advances towards azobenzene-based light-driven real-time information-transmitting materials. Beilstein J. Org. Chem.,  2012, 8, 1003-1017.
 [http://dx.doi.org/10.3762/bjoc.8.113] [PMID: 23019428]

[23]
Bandara, H.M.D.; Burdette, S.C. Photoisomerization in different classes of azobenzene. Chem. Soc. Rev.,  2012, 41(5), 1809-1825.
 [http://dx.doi.org/10.1039/C1CS15179G] [PMID: 22008710]

[24]
Beharry, A.A.; Woolley, G.A. Azobenzene photoswitches for biomolecules. Chem. Soc. Rev.,  2011, 40(8), 4422-4437.
 [http://dx.doi.org/10.1039/c1cs15023e] [PMID: 21483974]

[25]
Curtin, D.; Tveten, J.L. Reaction of diarylzinc reagents with aryldiazonium salts. 1 direct formation of cis-azo compounds. J. Org. Chem.,  1961, 26(6), 1764-1768.
 [http://dx.doi.org/10.1021/jo01065a017]

[26]
Neumann, W.P.; Wicenec, C. Tin for organic synthesis, 5 a new and regioselective synthesis of aromatic diazene derivatives. Chem. Ber.,  1991, 124(10), 2297-2301.
 [http://dx.doi.org/10.1002/cber.19911241023]

[27]
Haghbeen, K.; Tan, E.W. Facile synthesis of catechol azo dyes. J. Org. Chem.,  1998, 63(13), 4503-4505.
 [http://dx.doi.org/10.1021/jo972151z]

[28]
Barbero, M.; Degani, I.; Dughera, S.; Fochi, R.; Perracino, P. Preparation of diazenes by electrophilic c-coupling reactions of dry arenediazonium o-benzenedisulfonimides with grignard reagents. Synthesis,  1998, 1998(9), 1235-1237.
 [http://dx.doi.org/10.1055/s-1998-6102]

[29]
Merrington, J.; James, M.; Bradley, M. Supported diazonium salts-convenient reagents for the combinatorial synthesis of azo dye. Chem. Commun.,  2002, (2), 140-141.
 [http://dx.doi.org/10.1039/b109799g] [PMID: 12120342]

[30]
Davey, M.H.; Lee, V.Y.; Miller, R.D.; Marks, T.J. Synthesis of aryl nitroso derivatives by tert-butyl hypochlorite oxidation in homogeneous media. intermediates for the preparation of high-hyperpolarizability chromophore skeletons. J. Org. Chem.,  1999, 64(13), 4976-4979.
 [http://dx.doi.org/10.1021/jo990235x] [PMID: 11674586]

[31]
Ayyangar, N.R.; Naik, S.N.; Srinivasan, K.V. A novel synthesis of unsymmetrical azo aromatics inaccessible by diazo-coupling reaction. Tetrahedron Lett.,  1989, 30(51), 7253-7256.
 [http://dx.doi.org/10.1016/S0040-4039(01)93951-6]

[32]
Tombari, R.J.; Tuck, J.R.; Yardeny, N.; Gingrich, P.W.; Tantillo, D.J.; Olson, D.E. Calculated oxidation potentials predict reactivity in Baeyer–Mills reactions. Org. Biomol. Chem.,  2021, 19(35), 7575-7580.
 [http://dx.doi.org/10.1039/D1OB01450A] [PMID: 34524347]

[33]
Shimao, I.; Oae, S. The Wallach rearrangement of some 4, 4-disubstituted azoxybenzenes. Bull. Chem. Soc. Jpn.,  1983, 56(2), 643-644.
 [http://dx.doi.org/10.1246/bcsj.56.643]

[34]
Patel, A.R.; Patel, G.; Banerjee, S. Visible light-emitting diode light-driven Cu 0.9 Fe 0.1 @RCAC-catalyzed highly selective aerobic oxidation of alcohols and oxidative azo-coupling of anilines: Tandem one pot oxidation–condensation to imidazoles and imines. ACS Omega,  2019, 4(27), 22445-22455.
 [http://dx.doi.org/10.1021/acsomega.9b03096] [PMID: 31909327]

[35]
Grirrane, A.; Corma, A.; García, H. Gold-catalyzed synthesis of aromatic azo compounds from anilines and nitroaromatics. Science,  2008, 322(5908), 1661-1664.
 [http://dx.doi.org/10.1126/science.1166401] [PMID: 19074342]

[36]
Zhang, C.; Jiao, N. Copper-catalyzed aerobic oxidative dehydrogenative coupling of anilines leading to aromatic azo compounds using dioxygen as an oxidant. Angew. Chem. Int. Ed.,  2010, 49(35), 6174-6177.
 [http://dx.doi.org/10.1002/anie.201001651] [PMID: 20652918]

[37]
Lu, W.; Xi, C. CuCl-catalyzed aerobic oxidative reaction of primary aromatic amines. Tetrahedron Lett.,  2008, 49(25), 4011-4015.
 [http://dx.doi.org/10.1016/j.tetlet.2008.04.089]

[38]
Hosseini, S. An efficient and robust method for selective conversion of aniline to azobenzene using nano‐TiO2‐P25‐SO3H, under visible light irradiation. Photochem. Photobiol.,  2021, 97(2), 278-288.
 [http://dx.doi.org/10.1111/php.13328] [PMID: 32880982]

[39]
Cai, S.; Rong, H.; Yu, X.; Liu, X.; Wang, D.; He, W.; Li, Y. Room temperature activation of oxygen by monodispersed metal nanoparticles: Oxidative dehydrogenative coupling of anilines for azobenzene syntheses. ACS Catal.,  2013, 3(4), 478-486.
 [http://dx.doi.org/10.1021/cs300707y]

[40]
Yu, B.C.; Shirai, Y.; Tour, J.M. Syntheses of new functionalized azobenzenes for potential molecular electronic devices. Tetrahedron,  2006, 62(44), 10303-10310.
 [http://dx.doi.org/10.1016/j.tet.2006.08.069]

[41]
Miao, H.; Ma, K.; Hu, S.; Li, R.; Sun, L.; Cui, Y. Aerobic oxidative coupling of aniline catalyzed by one-dimensional manganese hydroxide nanomaterials. Synlett,  2019, 30(5), 552-556.
 [http://dx.doi.org/10.1055/s-0037-1612108]

[42]
Karunakaran, C.; Palanisamy, P.N. Autocatalysis in the sodium perborate oxidation of anilines in acetic acid–ethylene glycol. J. Mol. Catal. Chem.,  2001, 172(1-2), 9-17.
 [http://dx.doi.org/10.1016/S1381-1169(01)00113-3]

[43]
Saha, A.; Payra, S.; Selvaratnam, B.; Bhattacharya, S.; Pal, S.; Koodali, R.T.; Banerjee, S. Hierarchical mesoporous RuO2/Cu2O nanoparticle-catalyzed oxidative homo/Hetero Azo-coupling of anilines. ACS Sustain. Chem.& Eng.,  2018, 6(9), 11345-11352.
 [http://dx.doi.org/10.1021/acssuschemeng.8b01179]

[44]
Zhu, Y.; Shi, Y. Facile Cu(I)-catalyzed oxidative coupling of anilines to azo compounds and hydrazines with diaziridinone under mild conditions. Org. Lett.,  2013, 15(8), 1942-1945.
 [http://dx.doi.org/10.1021/ol4005917] [PMID: 23545123]

[45]
Okumura, S.; Lin, C.H.; Takeda, Y.; Minakata, S. Oxidative dimerization of (hetero)aromatic amines utilizing t-BuOI leading to (hetero)aromatic azo compounds: Scope and mechanistic studies. J. Org. Chem.,  2013, 78(23), 12090-12105.
 [http://dx.doi.org/10.1021/jo402120w] [PMID: 24175677]

[46]
Farhadi, S.; Zaringhdam, P.; Sahamieh, R.Z. Photo-assisted oxidation of anilines and other primary aromatic amines to azo compounds using mercury (II) oxide as a photo-oxidant. Acta Chim. Slov.,  2007, 54, 647-653.

[47]
Sun, Y.; Li, Y.; Li, Z.; Zhang, D.; Qiao, W.; Li, Y.; Niemantsverdriet, H.; Yin, W.; Su, R. Flat and stretched delafossite α-AgGaO2: Manipulating redox chemistry under visible light. ACS Catal.,  2021, 11(24), 15083-15088.
 [http://dx.doi.org/10.1021/acscatal.1c04686]

[48]
Han, S.; Cheng, Y.; Liu, S.; Tao, C.; Wang, A.; Wei, W.; Yu, H.; Wei, Y. Selective oxidation of anilines to azobenzenes and azoxybenzenes by a molecular mo oxide catalyst. Angew. Chem. Int. Ed.,  2021, 60(12), 6382-6385.
 [http://dx.doi.org/10.1002/anie.202013940] [PMID: 33350553]

[49]
Qiao, W.; Waseem, I.; Shang, G.; Wang, D.; Li, Y.; Besenbacher, F.; Niemantsverdriet, H.; Yan, C.; Su, R. Paired electrochemical N–N coupling employing a surface-hydroxylated Ni3Fe-MOF-OH bifunctional electrocatalyst with enhanced adsorption of nitroarenes and anilines. ACS Catal.,  2021, 11(21), 13510-13518.
 [http://dx.doi.org/10.1021/acscatal.1c03938]

[50]
Wang, G.; Zhang, J.; Hu, L.; Wang, J.; Zhu, C. Polydentate hydrazones as multitasking catalysts in visible-light-induced coupling reactions of amines. Org. Biomol. Chem.,  2023, 21(4), 754-760.
 [http://dx.doi.org/10.1039/D2OB02092K] [PMID: 36598776]

[51]
Han, X.; Zhang, T.; Wang, X.; Zhang, Z.; Li, Y.; Qin, Y.; Wang, B.; Han, A.; Liu, J. Hollow mesoporous atomically dispersed metal-nitrogen-carbon catalysts with enhanced diffusion for catalysis involving larger molecules. Nat. Commun.,  2022, 13(1), 2900.
 [http://dx.doi.org/10.1038/s41467-022-30520-3] [PMID: 35610219]

[52]
Cai, X.; Shen, Y.; Li, W.; Zhan, W.; Zhang, F.; Xu, C.; Song, H. Low-valent tungsten-catalyzed controllable oxidative dehydrogenative coupling of anilines. Org. Lett.,  2023, 25(1), 240-245.
 [http://dx.doi.org/10.1021/acs.orglett.2c04090] [PMID: 36573686]

[53]
Karunakaran, C.; Senthilvelan, S. Fe2O3-photocatalysis with sunlight and UV light: Oxidation of aniline. Electrochem. Commun.,  2006, 8(1), 95-101.
 [http://dx.doi.org/10.1016/j.elecom.2005.10.034]

[54]
Luo, L.; Liu, Y.; Chen, W.; Xue, X.; Xu, S-M.; Li, M.; Zhou, H.; Ma, L.; Xu, M.; Kong, X.; Shao, M.; Li, Z.; Duan, H. Photoelectrocatalytic synthesis of aromatic azo compounds over porous nanoarrays of bismuth vanadate. Chem Catalysis,  2023, 3(1), 100472.
 [http://dx.doi.org/10.1016/j.checat.2022.11.011]

[55]
Jiang, B.; Du, Y.Y.; Han, G.Z. Palladium-mediated base-free and solvent-free synthesis of aromatic azo compounds from anilines catalyzed by copper acetate. Green Process. Synth.,  2022, 11(1), 823-829.
 [http://dx.doi.org/10.1515/gps-2022-0070]

[56]
Damiano, C.; Cavalleri, M.; Panza, N.; Gallo, E. Cobalt porphyrin-catalysed synthesis of azobenzenes by dehydrogenative coupling of anilines. Eur. J. Chem.,  2022, 34, e202200791.

[57]
Griwatz, J.H.; Kunz, A.; Wegner, H.A. Continuous flow synthesis of azobenzenes via Baeyer–Mills reaction. Beilstein J. Org. Chem.,  2022, 18, 781-787.
 [http://dx.doi.org/10.3762/bjoc.18.78] [PMID: 35859625]

[58]
Antoine John, A.; Lin, Q. Synthesis of azobenzenes using N-chlorosuccinimide and 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU). J. Org. Chem.,  2017, 82(18), 9873-9876.
 [http://dx.doi.org/10.1021/acs.joc.7b01530] [PMID: 28846399]

[59]
Agarwal, S.; Dowara, B.; Kumar, S.; Kumar, V.; Deori, K. Magnetically separable visible light-active Ag0.75Ni0.25 binary alloy nanoparticles as a highly efficient photocatalyst for the selective oxidative coupling of aniline to azobenzene. ACS Omega,  2022, 7(51), 48615-48622.
 [http://dx.doi.org/10.1021/acsomega.2c07441] [PMID: 36591159]

[60]
Thakuri, A.; Banerjee, M.; Chatterjee, A. Microwave-assisted rapid and sustainable synthesis of unsymmetrical azo dyes by coupling of nitroarenes with aniline derivatives. iScience,  2022, 25(6), 104497.
 [http://dx.doi.org/10.1016/j.isci.2022.104497] [PMID: 35721466]

[61]
Nomura, Y.; Anzai, H.; Tarao, R.; Shiomi, K. Syntheses and ultraviolet spectra of aromatic azo compounds. III. Methoxyazobenzene derivatives. Bull. Chem. Soc. Jpn.,  1964, 37(7), 967-969.
 [http://dx.doi.org/10.1246/bcsj.37.967]

[62]
Valizadeh, H.; Amiri, M.; Hosseinzadeh, F. Nanoparticles of organosilane-based nitrite ionic liquid immobilized on silica for the diazotization of aniline derivatives and subsequent synthesis of azo dyes. Dyes Pigments,  2012, 92(3), 1308-1313.
 [http://dx.doi.org/10.1016/j.dyepig.2011.09.013]

[63]
Jiang, H.; Chen, Y.; Chen, B.; Xu, H.; Wan, W.; Deng, H.; Ma, K.; Wu, S.; Hao, J. Ag-initiated gem-difluoromethylenation of the nitrogen center of arenediazonium salts to gem-difluoromethylene azo compounds. Org. Lett.,  2017, 19(9), 2406-2409.
 [http://dx.doi.org/10.1021/acs.orglett.7b00936] [PMID: 28430453]

[64]
Dabbagh, H.A.; Teimouri, A.; Chermahini, A.N. Green and efficient diazotization and diazo coupling reactions on clays. Dyes Pigments,  2007, 73(2), 239-244.
 [http://dx.doi.org/10.1016/j.dyepig.2005.12.002]

[65]
Chermahini, A.N.; Doukheh, M.; Hassan, H.Z.; Bostanian, M. Application of modified clays in diazotization and azo coupling reactions in water. J. Ind. Eng. Chem.,  2012, 18(2), 826-833.
 [http://dx.doi.org/10.1016/j.jiec.2011.11.146]

[66]
Bamoniri, A.; Mirjalili, B.B.F.; Moshtael-Arani, N. Environmentally green approach to synthesize azo dyes based on 1-naphthol using nano BF3•SiO2 under solvent-free conditions. Green Chem. Lett. Rev.,  2014, 7(4), 393-403.
 [http://dx.doi.org/10.1080/17518253.2014.969786]

[67]
Valizadeh, H.; Shomali, A. A new nitrite ionic liquid (IL-ONO) as a nitrosonium source for the efficient diazotization of aniline derivatives and in-situ synthesis of azo dyes. Dyes Pigments,  2012, 92(3), 1138-1143.
 [http://dx.doi.org/10.1016/j.dyepig.2010.11.010]

[68]
Chakraborty, A.; Jana, S.; Kibriya, G.; Dey, A.; Hajra, A. tert-Butyl nitrite mediated azo coupling between anilines and imidazoheterocycles. RSC Advances,  2016, 6(41), 34146-34152.
 [http://dx.doi.org/10.1039/C6RA03070J]

[69]
Wendler, T.; Schütt, C.; Näther, C.; Herges, R. Photoswitchable azoheterocycles via coupling of lithiated imidazoles with benzenediazonium salts. J. Org. Chem.,  2012, 77(7), 3284-3287.
 [http://dx.doi.org/10.1021/jo202688x] [PMID: 22401292]

[70]
Zhang, Y.F.; Mellah, M. Convenient electrocatalytic synthesis of azobenzenes from nitroaromatic derivatives using SmI 2. ACS Catal.,  2017, 7(12), 8480-8486.
 [http://dx.doi.org/10.1021/acscatal.7b02940]

[71]
Zhu, H.; Ke, X.; Yang, X.; Sarina, S.; Liu, H. Reduction of nitroaromatic compounds on supported gold nanoparticles by visible and ultraviolet light. Angew. Chem. Int. Ed.,  2010, 49(50), 9657-9661.
 [http://dx.doi.org/10.1002/anie.201003908] [PMID: 21053223]

[72]
Sakai, N.; Asama, S.; Anai, S.; Konakahara, T. One-pot preparation of azobenzenes from nitrobenzenes by the combination of an indium-catalyzed reductive coupling and a subsequent oxidation. Tetrahedron,  2014, 70(11), 2027-2033.
 [http://dx.doi.org/10.1016/j.tet.2014.01.048]

[73]
Morales-Guio, C.G.; Yuranov, I.; Kiwi-Minsker, L. Highly selective catalytic reduction of nitro-to azoarenes under ambient conditions. Top. Catal.,  2014, 57(17-20), 1526-1532.
 [http://dx.doi.org/10.1007/s11244-014-0329-x]

[74]
Liu, X.; Ye, S.; Li, H.Q.; Liu, Y.M.; Cao, Y.; Fan, K.N. Mild, selective and switchable transfer reduction of nitroarenes catalyzed by supported gold nanoparticles. Catal. Sci. Technol.,  2013, 3(12), 3200-3206.
 [http://dx.doi.org/10.1039/c3cy00533j]

[75]
Kim, J.H.; Park, J.H.; Chung, Y.K.; Park, K.H. Ruthenium nanoparticle catalyzed, controlled and chemoselective hydrogenation of nitroarenes using ethanol as a hydrogen source. Adv. Synth. Catal.,  2012, 354(13), 2412-2418.
 [http://dx.doi.org/10.1002/adsc.201200356]

[76]
Teng, Y.; Wang, X.; Wang, M.; Liu, Q.; Shao, Y.; Li, H.; Liang, C.; Chen, X.; Wang, H. A schiff-base modified pt nano-catalyst for highly efficient synthesis of aromatic azo compounds. Catalysts,  2019, 9(4), 339.
 [http://dx.doi.org/10.3390/catal9040339]

[77]
Hu, L.; Cao, X.; Chen, L.; Zheng, J.; Lu, J.; Sun, X.; Gu, H. Highly efficient synthesis of aromatic azos catalyzed by unsupported ultra-thin Pt nanowires. Chem. Commun.,  2012, 48(28), 3445-3447.
 [http://dx.doi.org/10.1039/c2cc30281k] [PMID: 22367350]

[78]
Srinivasa, G.R.; Abiraj, K.; Gowda, D.C. The synthesis of azo compounds from nitro compounds using lead and triethylammonium formate. Tetrahedron Lett.,  2003, 44(31), 5835-5837.
 [http://dx.doi.org/10.1016/S0040-4039(03)01411-4]

[79]
Pasha, M.A.; Jayashankara, V.P. Reduction of arylnitro compounds to azoarenes and/or arylamines by Al/NaOH in methanol under ultrasonic conditions. Ultrason. Sonochem.,  2005, 12(6), 433-435.
 [http://dx.doi.org/10.1016/j.ultsonch.2004.07.002] [PMID: 15848104]

[80]
Liu, X.; Li, H.Q.; Ye, S.; Liu, Y.M.; He, H.Y.; Cao, Y. Gold-catalyzed direct hydrogenative coupling of nitroarenes to synthesize aromatic azo compounds. Angew. Chem. Int. Ed.,  2014, 53(29), 7624-7628.
 [http://dx.doi.org/10.1002/anie.201404543] [PMID: 24909452]

[81]
Srinivasa, G.R.; Abiraj, K.; Gowda, D.C. Facile synthesis of azo compounds from aromatic nitro compounds using magnesium and triethylammonium formate. Aust. J. Chem.,  2004, 57(6), 609-610.
 [http://dx.doi.org/10.1071/CH03143]

[82]
Hu, L.; Cao, X.; Shi, L.; Qi, F.; Guo, Z.; Lu, J.; Gu, H. A highly active nano-palladium catalyst for the preparation of aromatic azos under mild conditions. Org. Lett.,  2011, 13(20), 5640-5643.
 [http://dx.doi.org/10.1021/ol202362f] [PMID: 21939197]

[83]
Chen, W.; Li, H.; Jin, Y.; Wu, C.; Yuan, Z.; Ma, P.; Wang, J.; Niu, J. An intriguing tetranuclear Rh-based polyoxometalate for the reduction of nitroarene and oxidation of aniline. Chem. Commun.,  2022, 58(71), 9902-9905.
 [http://dx.doi.org/10.1039/D2CC03076D] [PMID: 35975716]

[84]
Sadatnabi, A.; Mohamadighader, N.; Nematollahi, D. Convergent paired electrochemical synthesis of azoxy and azo compounds: An insight into the reaction mechanism. Org. Lett.,  2021, 23(16), 6488-6493.
 [http://dx.doi.org/10.1021/acs.orglett.1c02304] [PMID: 34347493]

[85]
Mondal, B.; Mukherjee, P.S. Cage encapsulated gold nanoparticles as heterogeneous photocatalyst for facile and selective reduction of nitroarenes to azo compounds. J. Am. Chem. Soc.,  2018, 140(39), 12592-12601.
 [http://dx.doi.org/10.1021/jacs.8b07767] [PMID: 30199241]

[86]
Giomi, D.; Ceccarelli, J.; Salvini, A.; Pinto, M.; Brandi, A. Organocatalytic reduction of aromatic nitro compounds: The use of solid-supported phenyl(2-quinolyl)methanol. ACS Omega,  2022, 7(39), 35170-35179.
 [http://dx.doi.org/10.1021/acsomega.2c04196] [PMID: 36211086]

[87]
da Silva, M.A.R.; Rocha, G.F.S.R.; Diab, G.A.A.; Cunha, C.S.; Pastana, V.G.S.; Teixeira, I.F. Simple and straightforward method to prepare highly dispersed Ni sites for selective nitrobenzene coupling to Azo/Azoxy compounds. Chem. Eng. J.,  2023, 460, 141068.
 [http://dx.doi.org/10.1016/j.cej.2022.141068]

[88]
Qin, J.; Long, Y.; Sun, F.; Zhou, P.P.; Wang, W.D.; Luo, N.; Ma, J. Zr(OH) 4-Catalyzed controllable selective oxidation of anilines to azoxybenzenes, azobenzenes and nitrosobenzenes. Angew. Chem. Int. Ed.,  2022, 61(2), e202112907.
 [http://dx.doi.org/10.1002/anie.202112907] [PMID: 34643982]

[89]
Niu, Q.; Huang, Q.; Yu, T.Y.; Liu, J.; Shi, J.W.; Dong, L.Z.; Li, S.L.; Lan, Y.Q. Achieving high photo/thermocatalytic product selectivity and conversion via thorium clusters with switchable functional ligands. J. Am. Chem. Soc.,  2022, 144(40), 18586-18594.
 [http://dx.doi.org/10.1021/jacs.2c08258] [PMID: 36191239]

[90]
Lv, H.; Laishram, R.D.; Li, J.; Zhou, Y.; Xu, D.; More, S.; Dai, Y.; Fan, B. Photocatalyzed oxidative dehydrogenation of hydrazobenzenes to azobenzenes. Green Chem.,  2019, 21(15), 4055-4061.
 [http://dx.doi.org/10.1039/C9GC01235D]

[91]
Bai, L-S.; Gao, X-M.; Zhang, X.; Sun, F-F.; Ma, N. Photocatalyzed oxidative dehydrogenation of hydrazobenzenes to azobenzenes. Tetrahedron Lett.,  2014, 55(33), 4545-4548.
 [http://dx.doi.org/10.1016/j.tetlet.2014.06.097]

[92]
Barak, D.S.; Dighe, S.U.; Avasthi, I.; Batra, S. Iodine-catalyzed diazenylation with arylhydrazine hydrochlorides in air. J. Org. Chem.,  2018, 83(7), 3537-3546.
 [http://dx.doi.org/10.1021/acs.joc.7b03149] [PMID: 29486127]

[93]
Drug, E.; Gozin, M. Catalytic oxidation of hydrazo derivatives promoted by a TiCl3/HBr system. J. Am. Chem. Soc.,  2007, 129(45), 13784-13785.
 [http://dx.doi.org/10.1021/ja074413c] [PMID: 17958362]

[94]
Lim, Y.K.; Lee, K.S.; Cho, C.G. Novel route to azobenzenes via Pd-catalyzed coupling reactions of aryl hydrazides with aryl halides, followed by direct oxidations. Org. Lett.,  2003, 5(7), 979-982.
 [http://dx.doi.org/10.1021/ol027311u] [PMID: 12659553]

[95]
Yang, Y.; Hughes, R.P.; Aprahamian, I. Visible light switching of a BF2-coordinated azo compound. J. Am. Chem. Soc.,  2012, 134(37), 15221-15224.
 [http://dx.doi.org/10.1021/ja306030d] [PMID: 22954379]

[96]
Wang, Y.; Xie, R.; Huang, L.; Tian, Y-N.; Lv, S.; Kong, X.; Li, S.; Kong, X.; Li, S. Divergent synthesis of unsymmetrical azobenzenes via Cu-catalyzed C–N coupling. Org. Chem. Front.,  2021, 8(21), 5962-5967.
 [http://dx.doi.org/10.1039/D1QO00945A]

[97]
Lin, Y.; Wu, H.; Liu, Z.; Li, J.; Cai, R.; Hashimoto, M.; Wang, L. Additive-free aerobic oxidation of hydroazobenzenes: Access to azobenzenes and epoxidation of enones. Tetrahedron Lett.,  2022, 108, 154132.
 [http://dx.doi.org/10.1016/j.tetlet.2022.154132]

[98]
Powers, I.G.; Andjaba, J.M.; Luo, X.; Mei, J.; Uyeda, C. catalytic azoarene synthesis from aryl azides enabled by a dinuclear Ni complex. J. Am. Chem. Soc.,  2018, 140(11), 4110-4118.
 [http://dx.doi.org/10.1021/jacs.8b00503] [PMID: 29488760]

[99]
Liu, C.; Lv, J.; Luo, S.; Cheng, J.P. Sc(OTf)3-catalyzed transfer diazenylation of 1,3-dicarbonyls with triazenes via N-N bond cleavage. Org. Lett.,  2014, 16(20), 5458-5461.
 [http://dx.doi.org/10.1021/ol5027014] [PMID: 25295708]

[100]
Zhang, Y.; Liu, Y.; Ma, X.; Ma, X.; Wang, B.; Li, H.; Huang, Y.; Liu, C. An environmentally friendly approach to the green synthesis of azo dyes with aryltriazenes via ionic liquid promoted C-N bonds formation. Dyes Pigments,  2018, 158, 438-444.
 [http://dx.doi.org/10.1016/j.dyepig.2018.05.073]

[101]
Cao, D.; Zhang, Y.; Liu, C.; Wang, B.; Sun, Y.; Abdukadera, A.; Hu, H.; Liu, Q. Ionic liquid promoted diazenylation of N-heterocyclic compounds with aryltriazenes under mild conditions. Org. Lett.,  2016, 18(9), 2000-2003.
 [http://dx.doi.org/10.1021/acs.orglett.6b00605] [PMID: 27096379]

[102]
Baroliya, P.K.; Mehta, A.; Dashora, R.; Chauhan, R.S.; Goswami, A.K. Photocatalytic cleavage of hydroxytriazenes: A solid-state synthesis of azo-dyes under sunlight irradiation. Res. Chem. Intermed.,  2012, 38(9), 2149-2153.
 [http://dx.doi.org/10.1007/s11164-012-0533-x]
Rights & Permissions Print Cite
Journal Information
For Authors
For Editors
For Reviewers
Explore Articles
Open Access
Open Access Articles
For Visitors
DOI https://dx.doi.org/10.2174/0113852728245448231011103950	Print ISSN 1385-2728
Publisher Name Bentham Science Publisher	Online ISSN 1875-5348
Current Organic Chemistry

A Review on Traditional and Modern Methods for the Synthesis of Aromatic Azo Compounds

Abstract

Graphical Abstract

Catalytic C-H bond activation as a tool for functionalization of heterocycles

Current Organic Chemistry

A Review on Traditional and Modern Methods for the Synthesis of Aromatic Azo Compounds

Abstract Play Pause

Graphical Abstract

Call for Papers in Thematic Issues

Catalytic C-H bond activation as a tool for functionalization of heterocycles

Related Journals

Related Books

Abstract
