Copper Nanoparticles Immobilized on Nanocellulose: A Novel and Efficient Heterogeneous…
ethanol remained intact in the reaction mixture (confirmed
by GC-MS).
3. Shi F, Tse MK, Kaiser HM, Beller M (2007) Adv Synth Catal
49:2425–2430
Zhao P, Zhang M, Wu Y, Wang J (2012) Ind Eng Chem Res
3
4
.
To evaluate the reusability, the catalyst was separated by
simple filtration, washed with water and acetone for several
times and then used for next runs after further addition of
substrates in appropriate amount under identical conditions
and results are reported in (Fig. 3, SI). In order to rule out
the leaching of copper metal to the reaction media, hot filtra-
tion test was performed for the model reaction. The reaction
was stopped after 1 h to obtain a conversion of 60% (ana-
lyzed by GC–MS) and the solid catalyst was then hot-filtered
off. The filtrate part was then allowed to continue to react
for another 5 h. The product concentration in the filtrate was
found to be almost constant indicating that no Cu species
had leached to the reaction mixture.
5
1:6641–6647
5. Liu X, Xia Q, Zhang Y, Chen C, Chen W (2013) J Org Chem
78:8531–8536
6
.
Wang L, Shang S, Li G, Ren L, Lv Y, Gao S (2016) J Org Chem
8
1:2189–2193
7
.
Veisi H, Hemmati S, Qomi M (2017) Tetrahedron Lett
58:4191–4196
8. Kon Y, Yokoi T, Yoshioka M, Uesaka Y, Kujira H, Sato K, Tat-
sumi T (2013) Tetrahedron Lett 54:4918–4921
9
. Kinen CO, Rossi LI, Rossi RH (2009) J Org Chem 74:7132–7139
1
0. Trivedi R, Lalitha P (2006) Synth Commun 36:3777–3782
11. Bahrami K (2006) Tetrahedron Lett 47:2009–2012
12. Velusamy S, Kumar AV, Saini R, Punniyamurthy T (2005) Tetra-
hedron Lett 46:3819–3822
1
3. Jayaseeli AMI, Ramdass A, Rajagopal S (2015) Polyhedron
1
00:59–66
1
4. Rezaeifard A, Haddad R, Jafarpour J, Hakimi M (2014) ACS Sus-
tain Chem Eng 2:942–950
1
1
5. Wu XF (2012) Tetrahedron Lett 53:4328–4331
6. Sato K, Hyodo M, Aoki M, Zheng XQ, Noyori R (2001) Tetrahe-
dron 57:2469–2476
4
Conclusions
In summary, we have developed a low metal loading
CuNPs/NC as efficient and versatile catalyst for eco-friendly
oxidation of various sulfides to sulfoxides using 30% H O
17. Islam SM, Roy AS, Mondal P, Salam N, Paul S (2013) Catal Lett
143:225–233
1
8. Wang Q, Du W, Liu T, Chai H, Yu Z (2014) Tetrahedron Lett
2
2
5
5:1585–1588
at room temperature and selective oxidation of primary
alcohols to aldehydes using TEMPO as nitroxyl radical in
1
9. Panwar V, Kumar P, Ray SS, Jain SL (2015) Tetrahedron Lett
56:3948–3953
H O/EG media at room temperature. Use of biodegradable
20. Norman ROC, Coxon JM (1993) Principles of organic synthesis,
2
3
rd edn. Blackie Academic & Proffesional, London
support material, low metal loading (< 1 mol%), high yield
of oxidized products, short reaction time and room tem-
perature reaction conditions make this sulfides oxidation
protocol more advantageous than the existing protocols. On
the other hand, low metal loading, green solvent media,
ligand- and base-free conditions are the major advantages
of our catalyst system in alcohol oxidation reactions. The
benzylic and allylic alcohols were oxidized with excellent
yields, whereas aliphatic alcohols were less reactive and
required long reaction time. Both the oxidation systems are
simple and mild and the copper catalyst can be recycled and
reused up to 5th cycle without significant loss of catalytic
activity. This work can be considered as a very good step
towards the promising trend of heterogeneous and environ-
mental friendly transformations of organic compounds.
2
2
1. Skibida IP, Sakharow AM (1996) Catal Today 27:187–193
2. Noyori R, Aoki M, Sato K (2003) Chem Commun 36:
1977–1986
23. Jiang J, Du J, Wang Z, Zhang Z, Xu X, Zheng G, Ji Y (2014)
Tetrahedron Lett 55:1677–1681
2
4. Dhakshinamoorthy A, Alvaro M, Garcia H (2011) ACS Catal
1
:48–53
25. Ansari IA, Gree R (2002) Org Lett 4:1507–1509
26. Albadi J, Alihoseinzadeh A, Mansournezhad A (2015) Synth
Commun 45:877–885
2
7. Pande S, Saha A, Jana S, Sarkar S, Basu M, Pradhan M, Sinha
AK, Saha S, Pal A, Pal T (2008) Org Lett 10:5179–5181
28. Hoover JM, Ryland BL, Stahl SS (2013) J Am Chem Soc
135:2357–2367
2
3
9. Badalyan A, Stah SS (2016) Nature 535:406–410
0. Xie J, Yin K, Serov A, Artyushkova K, Pham HN, Sang X, Unocic
RR, Atanassov P, Datye AK, Davis RJ (2016) ChemSusChem
10:359–362
3
1. Chetia M, Ali AA, Bordoloi A, Sarma D (2017) J Chem Sci
129:1211–1217
Acknowledgements The authors acknowledge the Department of Sci-
ence and Technology for financial assistance under DST-FIST program
and UGC, New Delhi for Special Assistance Programme (UGC-SAP)
to the Department of Chemistry, Dibrugarh University.
32. Kaushik M, Moores A (2016) Green Chem 18:622–637
33. Goswami M, Das AM (2018) Carbohydr Polym 195:189–198
34. Eivazihollagh A, Bäckström J, Dahlström C, Carlsson F, Ibra-
hem I, Lindman B, Edlund H, Norgren M (2017) Mater Lett
1
87:170–172
3
3
5. Musa A, Ahmad MB, Hussein MZ, Izham SM, Shameli K, Sani
HA (2016) J Nanomater 11:438
References
6. Eivazihollagh A, Norgren M, Dahlström C, Edlund H (2018)
Nanomaterials 8:238
1
2
.
.
Tojo G, Fernández M (2006) Oxidation of alcohols to aldehydes
and ketones, 1st edn. Springer, New York
37. Lahiji RR, Xu X, Reifenberger R, Raman A, Rudie A, Moon RJ
(2010) Langmuir 26:4480–4488
Centi G, Cavani F, Trifiro F (2001) Selective oxidation by het-
erogeneous catalysis, 1st edn. Kluwer Academic Publishers, New
York
38. Mora’n JI, Alvarez VA, Cyras VP, Va’zquez A (2015) Cellulose
15:149–159
1
3