Paper
NJC
and furnished the reduced products 2p–r without affecting the
ring nitrogen atom (Table 5). Thus, these results reveal the
usefulness of the protocol.
5 X. Lang, X. Chen and J. Zhao, Chem. Soc. Rev., 2014, 43,
473–486.
6 D. Ravelli, M. Fagnoni and A. Albini, Chem. Soc. Rev., 2013,
42, 97–113.
7
8
D. W. MacMillan, Nature, 2008, 455, 304–308.
N. A. Romero and D. A. Nicewicz, Chem. Rev., 2016, 116,
1
Mechanism
It is expected that Co(II) is responsible for reduction of nitro
groups. In a typical reaction sequence, Co(II) reduces the nitro
groups to amines and gets converted into its oxidized form
Co(III). Then, Co(III) is reduced by the reductant hydrazine
monohydrate, as shown in Scheme 1. As XPS confirms the
presence of bivalent cobalt, the catalytic cycle proceeds via
Co(II)/Co(III) couple. The nitroarene reduction reactions were
performed with a catalytic amount of catalyst B, which proceeds
via Co(III) reduction to Co(II) by hydrazine monohydrate.
0075–10166.
C. K. Prier, D. A. Rankic and D. W. MacMillan, Chem. Rev.,
013, 113, 5322–5363.
0 D. A. Nicewicz and D. W. MacMillan, Science, 2008, 322,
7–80.
1 D. A. Nagib and D. W. MacMillan, Nature, 2011, 480,
24–228.
2 A. McNally, C. K. Prier and D. W. MacMillan, Science, 2011,
34, 1114–1117.
3 M. A. Ischay, M. E. Anzovino, J. Du and T. P. Yoon, J. Am.
Chem. Soc., 2008, 130, 12886–12887.
4 T. P. Yoon, M. A. Ischay and J. Du, Nat. Chem., 2010, 2,
27–532.
5 J. Du, K. L. Skubi, D. M. Schultz and T. P. Yoon, Science,
014, 344, 392–396.
6 J. M. Narayanam, J. W. Tucker and C. R. Stephenson, J. Am.
Chem. Soc., 2009, 131, 8756–8757.
9
2
1
1
1
1
1
1
1
1
1
1
7
2
3
Conclusions
5
In conclusion, a solid-state method for the preparation of
CoO@amorphous-TiO (CoO@TiO ) was performed success-
2 2
fully. Various physico-chemical characterization techniques
indicated the formation of TiO , the presence of nano-sized
cobalt oxide where Co was in 2+ oxidation state, and good
absorption in the visible range. The resulting catalyst was
tested for visible light-assisted selective reduction of nitro-
arenes to the corresponding amino compounds. The scope
of this study was extended to various nitro compounds
including substituted nitroarenes. Additionally, the optimized
catalyst was also active for the chemo-selective hydrogenation of
nitroarenes.
2
2
7 J. M. Narayanam and C. R. Stephenson, Chem. Soc. Rev.,
2
011, 40, 102–113.
8 X. Yu, L. Wang and S. M. Cohen, CrystEngComm, 2017, 19,
126–4136.
4
9 G. L. Chiarello, L. Forni and E. Selli, Catal. Today, 2009, 144,
69–74.
20 K. A. Kumar, S. R. Amanchi, B. Sreedhar, P. Ghosal and
C. Subrahmanyam, RSC Adv., 2017, 68, 43030–43039.
2
2
2
2
2
2
2
2
1 O. Beswick, A. Parastaev, I. Yuranov, T. LaGrange, P. J.
Dyson and L. Kiwi-Minsker, Catal. Today, 2017, 279, 29–35.
2 B. Lakshminarayana, G. Satyanarayana and Ch. Subrahmanyam,
ACS Omega, 2018, 3, 13065–13072.
3 P. Eskandari, F. Kazemi and Z. Zand, J. Photochem. Photobiol.,
A, 2014, 274, 7–12.
4 X. Guo, C. Hao, G. Jin, H. Y. Zhu and X. Y. Guo, Angew.
Chem., Int. Ed., 2014, 53, 1973–1977.
5 K. Tsutsumi, F. Uchikawa, K. Sakai and K. Tabata, ACS
Catal., 2016, 6, 4394–4398.
Conflicts of interest
There are no conflicts to declare.
Acknowledgements
Dr Srinivasa Rao Amanchi, would like to acknowledge DST-SERB
for financial support with project number YSS/2015/001222. The
authors thank MHRD-India (CE/2014-15/020/MHRD/KVLS/0130)
for financial assistance.
6 A. Kaushik, B. Dalela, S. Kumar, P. A. Alvi and S. Dalela,
J. Alloys Compd., 2013, 552, 274–278.
7 B. Su, Z. C. Cao and Z. J. Shi, Acc. Chem. Res., 2015, 3,
886–896.
References
8 A. Dashora, R. Varma, D. C. Kothari and B. L. Ahuja, Appl.
Catal., B, 2016, 183, 242–253.
1
2
3
Z. Hu, H. Quan, Z. Chen, Y. Shao and D. Li, Photochem.
Photobiol. Sci., 2018, 17, 51–59.
Y. Wu, X. Ye, S. Zhang, S. Meng, X. Fu, X. Wang, X. Zhang
and S. Chen, J. Catal., 2018, 359, 151–160.
29 B. Choudhury and A. Choudhury, J. Lumin., 2012, 132,
178–184.
30 K. Li, J. Zhang, R. Wu, Y. Yu and B. Zhang, Advanced Science,
2016, 3, 1500426.
T. Kahl, K. W. Schr o¨ der, F. R. Lawrence, W. J. Marshall,
H. H o¨ ke and R. J ¨a ckh, Aniline, in Ullmann’s Encyclopedia of 31 L. S. Sundar, G. O. Irurueta, E. V. Ramana, M. K. Singh and
Industrial Chemistry, Wiley-VCH Verlag, GmbH, Co. KGaA,
000.
A. C. M. Sousa, Case studies in thermal engineering, 2016, 7,
66–77.
2
4
H. U. Blaser., H. Steiner and M. Studer, ChemCatChem, 32 S. N. Hoseini, A. K. Pirzaman, M. A. Aroon and A. E.
009, 1, 210–221. Pirbazari, J. Waterprocesseng., 2017, 17, 124–134.
2
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