4
Tetrahedron Letters
copper enamide (6). Then there is Michael attack of 6 to 2-
The authors thank DST-JSPS for project (File No.
DST/INT/JSPS/P-214/2016) for the financial assistance. M.R.
acknowledges CSIR for the award of Shyama Prasad Mukherjee
Fellowship (File No: SPM-09/045(0249)/2016-EMR-I). We
thank USIC-CIF, University of Delhi, for assistance in acquiring
analytical data.
benzylidenemalononitrile (5) which is generated by aldehyde and
malononitrile followed by intramolecular addition and oxidation
leads to formation of desired product 4. The final product can be
confirmed by X-ray single crystal diffraction analysis of one of
the derivative 4n (Figure 6).
References and notes
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Figure 6: X-ray crystallography structure of compound 4n (CCDC
1875933).
3. Rostovshchikova, T. N.; Smirnov, V. V.; Kozhevin, V.
M.; Yavsin, D. A.; Zabelin, M. A.; Yassievich, I. N.;
Gurevich, S. A. Appl. Catal. A: Gen. 2005, 296, 70–79.
The recyclability of catalyst was checked for a model reaction
to afford desired product under optimized condition. Catalyst was
recovered by addition of ethanol followed by centrifugation,
washed with ethanol several times and dried in oven. Recovered
catalyst was reused for five more times without drastic change in
percentage yield of product as showed in Figure 7. Results
clearly showed that catalyst can be used several times without
losing their catalytic activity results in less loss in percentage
yield of product.
4. Mirkin, C. A. Small, 2005, 1, 14–16.
5. White, R. J.; Luque, R.; Budarin, V. L.; Clark, J. H.;
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Romero, A. ChemSusChem: Chemistry & Sustainability
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7. Henrich V. E.; Cox, P. A. The Surface Science of Metal
To check the sustainability of present method, green chemistry
metrices was calculated for 4c (Table 3). Results clearly showed
the values are quite close to ideal one with low E-factor (0.49),
low PMI (1.49), high RME (66.74%), high atom economy
(78.5%) and high TON (48). (detailed calculations in supporting
file).
Oxides; Cambridge University Press: New York, 1994.
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Huang, X.; Silva, R.; Zou, X.; Zboril, R.; Varma, R. S.
Chem. Rev. 2016,116, 3722–3811.
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Figure 7: Recyclability of CuI@Al2O3 nanocatalyst for synthesis of 4c.
Table 3. Green chemistry metrices
15. Zou, X.; Rui, Z.; Ji, H. ACS Catal. 2017, 7, 1615–1625.
Entry Catalyst
E-
factor
0.49
77.3
PMI RME
Atom
Economy
TON
16. Lancelot, C.; Ordomsky, V. . t an, . ade ade ,
. Karaca, . Lacro , . Curulla- err , D.; Luck, F.;
Fongarland, P.; Griboval-Constant, A.; Khodakov, A. Y.
ACS Catal. 2014, 4, 4510–4515.
1.
2.
CuI@Al2O3
1.49 66.74 % 78.5 %
78.3 28.91 % 70.3 %
48.0
0.60
CuI
(Scheme 1)30
17. Zhang, Q. C.; Liu, Z. W.; Zhu, X. H.; Wen, L. X.; Zhu,
Q. F.; Guo, K.; Chen, J. F. Ind. Eng. Chem. Res. 2015,
54, 8874–8882.
Conclusion:
In summary, we have developed CuI@Al2O3 synthesis of 2-
18. Rajesh, U. C.; Gulati, U.; Rawat, D. S. ACS Sustain.
Chem. Eng. 2016, 4, 3409–3419.
aminonicotinonitrile using oxime acetate, aldehyde and
malononitrile as starting material without the use of any additives
under solvent free condition. The present method was found to be
greener and more sustainable as compared with literature
methods with low E value which clearly shows the less waste
generation. Nanocatalyst can be recycled and reused five times
without significant loss of its catalytical activity.
19. Sharma, R. K., Rashmi, G.; Manavi, Y.; Rathi, A. K., Jiri,
P.; Martin, P.; Radek, Z.; Gawande, M. B.
ChemCatChem. 2015, 7, 3495–3502.
20. Gawande, M. B.; Goswami, A.; Felpin, F. X.; Asefa, T.;
Huang, X.; Silva, R.; Zou, X.; Zboril, R.; Varma, R. S.
Chem. Rev. 2016, 116, 3722–3811.
Acknowledgements