Liu et al.
71
catalysis could be an interesting methodology. Further appli-
cations are currently under investigation in our laboratory.
(4) Gu, Y. L.; Li, G. X. Adv. Synth. Catal. 2009, 351 (6), 817.
doi:10.1002/adsc.200900043.
(
5) Mehnert, C. P.; Cook, R. A.; Dispenziere, N. C.; Afeworki,
M. J. Am. Chem. Soc. 2002, 124 (44), 12932. doi:10.1021/
ja0279242.
Experimental
The ionic liquid [bmim]PF was synthesized according to
(6) Riisager, A.; Fehrmann, R.; Flicker, S.; van Hal, R.; Hau-
mann, M.; Wasserscheid, P. Angew. Chem. Int. Ed. 2005, 44
(5), 815. doi:10.1002/anie.200461534.
6
the literature.27 Silica gel (200–300 mesh) was activated at
180 8C under vacuum overnight before use. All other chem-
icals were obtained from commercial sources with more
than 99% purity and used without further purification. Gas
chromatography (GC) analysis was performed on an Agilent
GC-6820 equipped with a 30 m  0.32 mm  0.5 mm HP-
Innowax capillary column and a flame ionization detector.
The elemental analysis of copper was determined by induc-
tively coupled plasma atomic emission spectroscopy
(7) Mehnert, C. P.; Mozeleski, E. J.; Cook, R. A. Chem. Com-
mun. (Camb.) 2002, (24): 3010. doi:10.1039/b210214e.
(8) Kume, Y.; Qiao, K.; Tomida, D.; Yokoyama, C. Catal. Com-
mun. 2008, 9 (3), 369. doi:10.1016/j.catcom.2007.07.012.
(
9) Qiao, K.; Sugimura, R.; Bao, Q.; Tomida, D.; Yokoyama, C.
Catal. Commun. 2008, 9 (15), 2470. doi:10.1016/j.catcom.
2
008.06.016.
(
10) Tao, R.; Miao, S.; Liu, Z.; Xie, Y.; Han, B.; An, G.; Ding,
K. Green Chem. 2009, 11 (1), 96. doi:10.1039/b811587g.
11) Jimenez, O.; M u¨ ller, T. E.; Sievers, C.; Spirkl, A.; Lercher,
J. A. Chem. Commun. (Camb.) 2006, (28): 2974. doi:10.
(
Thermo Scientific iCAP 6300). Products were all known
compounds and were identified by comparing their physical
and spectral data with those reported in the literature.
(
1
039/b605567b.
Catalyst preparation
(
12) Likhar, P. R.; Roy, S.; Roy, M.; Subhas, M. S.; Kantam, M.
TEMPO-IL was prepared according to the literature.28 To
a stirred solution of TEMPO-IL (1.0 g, 2.26 mmol) in
L. Catal. Commun. 2009, 10 (5), 728. doi:10.1016/j.catcom.
2
008.11.026.
2
5 mL of methanol, CuCl Á2H O (0.386 g, 2.26 mmol) was
2
2
(13) Lou, L. L.; Yu, K.; Ding, F.; Peng, X.; Dong, M.; Zhang, C.;
Liu, S. J. Catal. 2007, 249 (1), 102. doi:10.1016/j.jcat.2007.
03.016.
(14) Buffin, B. P.; Clarkson, J. P.; Belitz, N. L.; Kundu, A. J.
Mol. Catal. Chem. 2005, 225 (1), 111. doi:10.1016/j.
molcata.2004.08.035.
added. After that, silica gel (3.15 g) was added. The mixture
was stirred for 5 h and then evaporated under reduced pres-
sure for 3 h to give a powder of TEMPO-IL/CuCl /SiO .
2
2
The obtained product was dried at 50 8C under vacuum
overnight before use.
(
15) Kato, C. N.; Shinohara, A.; Moriya, N.; Nomiya, K. Catal.
Commun. 2006, 7 (6), 413. doi:10.1016/j.catcom.2005.12.
Typical experimental procedure for oxidation of alcohols
0
16.
Alcohol (1 mmol) and TEMPO-IL/CuCl /SiO (100 mg)
2
2
(
16) Figiel, P. J.; Sibaouih, A.; Ahmad, J. U.; Nieger, M.; R a¨ is a¨ -
were mixed with n-octane (10 mL) and stirred at 70 8C
nen, M. T.; Leskela, M.; Repo, T. Adv. Synth. Catal. 2009,
under O (10 mL/min, 1 atm (1 atm = 101.325 kPa)) for the
2
3
51 (16), 2625. doi:10.1002/adsc.200900478.
17) Kumpulainen, E. T. T.; Koskinen, A. M. P. Chem. Eur. J.
009, 15 (41), 10901. doi:10.1002/chem.200901245.
given time. After completion (monitored by TLC and GC),
the mixture was centrifuged to separate the catalyst, which
was washed several times with n-octane, dried, and re-
charged with fresh substrate and solvent for the next cata-
lytic cycle. The combined solvent phase was concentrated
under vacuum, and the crude product was purified by col-
umn chromatography (petroleum ether / ethyl acetate, 10/1)
to provide the analytically pure aldehyde, which was charac-
(
(
(
(
2
18) Huang, G.; Cai, C. C.; Luo, J.; Zhou, H.; Guo, Y. A.; Liu, S.
Y. Can. J. Chem. 2008, 86 (3), 199. doi:10.1139/V08-002.
19) Jiang, N.; Ragauskas, A. J. Tetrahedron Lett. 2007, 48 (2),
2
73. doi:10.1016/j.tetlet.2006.11.032.
20) Gheorghe, A.; Matsuno, A.; Reiser, O. Adv. Synth. Catal.
006, 348 (9), 1016. doi:10.1002/adsc.200606043.
2
1
terized by H NMR and IR analysis.
(21) Miao, C. X.; He, L. N.; Wang, J. Q.; Wang, J. L. Adv. Synth.
Catal. 2009, 351 (13), 2209. doi:10.1002/adsc.200900285.
(22) Dijksman, A.; Arends, I.; Sheldon, R. A. Synlett 2001, 102.
Acknowledgements
(
(
(
23) Liu, L.; Liuyan, J.; Yunyang, W. Catal. Commun. 2008, 9
6), 1379. doi:10.1016/j.catcom.2007.11.041.
24) Liu, L.; Ji, L.-Y.; Wei, Y.-Y. Monatsh. Chem. 2008, 139 (8),
01. doi:10.1007/s00706-008-0861-0.
25) Lin, L.; Juanjuan, M.; Liuyan, J.; Yunyang, W. J. Mol.
Catal. Chem. 2008, 291 (1–2), 1. doi:10.1016/j.molcata.
This work was supported by National Natural Science
Foundation of China (grant No. 50873042) and the Scien-
tific Research Program of the HuaiHai Institute of Technol-
ogy (Z2009015, Z2009021).
(
9
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