J IRAN CHEM SOC
Table 6 Elemental analysis results of the fresh Pd–2C–1N catalyst
and reused Pd–2C–1N catalyst
it can be homogeneous during the reaction to enhance the
conversions of the substrates. The feature also benefits the
recycle and reuse of the catalyst by adding HCl or NaOH.
Moreover, the catalyst is stable enough to be reused for at
least five runs without any loss or decomposition.
Samples
N (wt %)
C (wt %)
Fresh Pd–2C–1N
2.87
2.65
23.64
22.98
Pd–2C–1N after the 5th run
References
information, run 1, middle photo). The upper organic layer
was decanted. Then pH was readjusted to 9–10 with NaOH
solution. Fresh ether and alcohols were added to the above
mixture. The catalysts came back to the organic phase again
1
. L.M. Berkowitz, P.N. Rylander, J. Am. Chem. Soc. 80, 6682
1958)
. P. Gamez, I.W.C.E. Arends, J. Reedijk, R.A. Sheldon, Chem.
Commun. 2414 (2003)
(
2
(
Figure S3, supporting information, run 1, right photo).
3. I.E. Marko, A. Gautier, R. Dumeunier, K. Doda, F. Philippart,
S.M. Brown, C.J. Urch, Angew. Chem. Int. Ed. 43, 1588 (2004)
Afterward, the next reaction could be carried out. From the
second cycle to the fifth run, the activity and selectivity had
no obvious decreases. All five cycles achieved about 65 %
of conversion and above 90 % of selectivity. Throughout
five cycles, the catalysts could be recycled with the phase
transfer strategy (Figure S3, supporting information, runs
4
5
. N. Jiang, A.J. Ragauskas, J. Org. Chem. 71, 7087 (2006)
. O. Onomura, H. Arimoto, Y. Matsumura, Y. Demizu, Tetrahedron.
Lett. 48, 8668 (2007)
6. P.J. Figiel, M.N. Kopylovich, J. Lasri, M.F.F.C. Guedes da Silva,
J.J.R. Frau_sto da Silva, A.J.L. Pombeiro, Chem. Commun.
2
766(2010)
7
8
. J.M. Hoover, S.S. Stahl, J. Am. Chem. Soc. 133, 16901 (2011)
. C. Han, M. Yu, W. Sun, X. Yao, Synlett. 2363(2011)
2
–5). The whole separation and recycling process is suit-
able for all the catalysts we synthesized.
9. S.G. Babu, P.A. Priyadarsini, R. Karvembu, Appl. Catal. A: Gen.
92, 218 (2011)
3
To test the stability of catalysts, the residual Pd con-
tents after recycling in the organic layer and water layer
were determined with ICP-AES. For comparison, the con-
centration of Pd during the reaction in the organic phase
and water phase was also examined. During the reaction,
Pd concentration was as high as 45 ug/mL (Table 5) in the
organic layer, and the Pd residue in water in the reaction
was only 0.029 ug/mL (Table 5). The results suggest that
the catalyst was well dispersed, thus making the reaction
homogeneous in the organic phase. After HCl was added
and the catalyst returned to the water phase, the Pd con-
centration was only 0.25 in the ether phase in the first run
1
1
0. R. Dileep, B.R. Bhat, Appl. Organometal. Chem. 24, 663 (2010)
1. B.Z. Zhan, M.A. White, T.K. Sham, J.A. Pincock, R.J. Doucet,
K.V.R. Rao, K.N. Robertson, T.S. Cameron, J. Am. Chem. Soc.
125, 2195 (2003)
2. H. Tsunoyama, H. Sakurai, Y. Negishi, T. Tsukuda, J. Am. Chem.
Soc. 127, 9374 (2005)
1
1
3. B. Guan, D. Xing, G. Cai, X. Wan, N. Yu, Z. Fang, L. Yang, Z.
Shi, J. Am. Chem. Soc. 127, 18004 (2005)
14. J. Ni, W.J. Yu, L. He, H. Sun, Y. Cao, H. He, K. Fan, Green Chem.
1, 756 (2009)
1
1
1
5. Y. Uozumi, R. Nakao, Angew. Chem. Int. Ed. 42, 194–197 (2003)
6. Z. Hou, N. Theyssen, A. Brinkmann, W. Leitner, Angew. Chem.
1
17, 1370–1373 (2005)
17. P. Zhang, Y. Gong, H. Li, Z. Chen, Y. Wang, Nature Commun. 4,
593 (2013)
8. H. Wang, H. Yang, H. Liu, Y. Yu, H. Xin, Langmuir 29, 6687–
696 (2013)
1
(Table 5, Cycle 1). In the next four runs, the Pd contents
1
1
2
2
were 0.031, 0.038, 0.038 and 0.039, respectively (Table 5,
Cycle 2 to Cycle 5). The results indicate that the phase
transfer is complete and these catalysts are stable for at
least five cycles. In addition, the elemental analysis was
used to ensure that the carriers stick to Pd nanoparticles
without loss or decomposition. The results are summarized
in Table 6. It can be seen that C and N contents of the cata-
lysts after being recycled four times were similar to those
of the fresh catalysts, thus demonstrating that the carriers
were also stable.
6
9. R. Dun, X. Wang, M. Tan, Z. Huang, X. Huang, W. Ding, ACS
Catal. 3, 3063–3066 (2013)
0. B. Karimi, S. Abedi, J.H. Clark, V. Budarin, X.G. Lu, Angew.
Chem. Int. Ed. 45, 4776–4779 (2006)
1. H. Li, H. Jiang, R. Chen, Y. Wang, W. Xing, Int. Eng. Chem. Res.
5
2, 14099–14106 (2013)
22. R. Chen, Y. Jiang, W. Xing, W. Jin, Int. Eng. Chem. Res. 52,
002–5008 (2013)
5
2
3. T.T. Isimjian, Q. He, Y. Liu, J. Zhu, R.J. Puddephatt, D.J. Ander-
son, ACS Sustainable Chem. Eng. 1(4), 381–388 (2013)
4. B. Fu, X. Zhu, G. Xiao, Appl. Catal. A 415–416, 47–52 (2012)
5. A. Villa, D. Wang, N. Dimitratos, D.S. Sub, V. Trevisanc, L. Prati,
Catal. Today 150, 8–15 (2010)
2
2
2
2
6. C.M.A. Parlett, D. Bruce, V. Hondow, A. Lee, K. Wilson, ACS
Catal. 1(6), 636–640 (2011)
7. K. Mori, T. Hara, T. Mizugaki, K. Ebitani, K. Kaneda, J. Am.
Chem. Soc. 126, 10657–10666 (2004)
8. B.P. Binks, S.O. Lumsdon, Langmuir 16, 8622–8631 (2000)
9. C. Xiao, L. Mingdao, Interface Chemistry, 1st edn. (Chemical
Industry Press, Beijing, 2004)
Conclusion
In summary, we developed a catalyst composed of nano-
composite shuttle-supported palladium nanoparticles. Its
employment in the oxidation of primary alcohols and sec-
ondary alcohols results in high efficiency and excellent
selectivity. The catalyst can be pH triggered. Therefore,
2
2
3
0. M.S. Sigman, D.R. Jensen, Acc. Chem. Res. 39, 221 (2006)
1
3