Table 3 Recycling and reuse of the fluorous catalyst by filtration
5 (a) M. Mulbaier and A. Giannis, Angew. Chem., Int. Ed., 2001, 40,
¨
4393–4394; (b) G. Sorg, A. Mengel, G. Jung and J. Rademann,
Angew. Chem., Int. Ed., 2001, 40, 4395–4397; (c) N. N. Reed,
M. Delgado, K. Hereford, B. Clapham and K. D. Janda, Bioorg.
Med. Chem. Lett., 2002, 12, 2047–2049; (d) Z. Lei, C. Denecker,
S. Jegasothy, D. C. Sherrington, N. K. H. Slater and
A. J. Sutherland, Tetrahedron Lett., 2003, 44, 1635–1637;
(e) W.-J. Chung, D.-K. Kim and Y.-S. Lee, Synlett, 2005,
2175–2178; (f) Z. Q. Lei, H. C. Ma, Z. Zhang and Y. X. Yang,
React. Funct. Polym., 2006, 66, 840.
6 For catalytic IBX, see: (a) A. P. Thottumkara, M. S. Bowsher and
T. K. Vinod, Org. Lett., 2005, 7, 2933–2936; (b) A. Schulze and
A. Giannis, Synthesis, 2006, 257–260.
7 For catalytic IBS, see: M. Uyanik, M. Akakura and K. Ishihara,
J. Am. Chem. Soc., 2009, 131, 251–262.
8 For selected reviews on organocatalysts, see: (a) P. I. Dalko and
L. Moisan, Angew. Chem., Int. Ed., 2004, 43, 5138–5175;
(b) H. Pellissier, Tetrahedron, 2007, 63, 9267–9331;
(c) S. Mukherjee, J. W. Yang, S. Hoffmann and B. List, Chem.
Rev., 2007, 107, 5471–5569; (d) A. Dondoni and A. Massi, Angew.
Chem., Int. Ed., 2008, 47, 4638–4660; (e) A. Lattanzi, Chem.
Commun., 2009, 1452–1463; (f) X. Liu, L. Lin and X. Feng, Chem.
Commun., 2009, 6145–6158.
Entry
Time/h
Yielda (%)
Cat. recoveryb
Initial
9
9
9
9
10
10
83
82
91
95
94
88
100
100
100
84
91
65
First reuse
Second reuse
Third reuse
Fourth reuse
Fifth reuse
a
b
Isolated yield. Determined by weight of recovered fluorous
IBA (9).
9 For a review on the fluorous tag technique, see (a) D. P. Curran,
Synlett, 2001, 1488–1496; (b) D. P. Curran, in The Handbook of
Fluorous Chemistry, ed. J. A. Gladysz, I. T. Horvath and
´
D. P. Curran, Wiley-VCH, Weinheim, 2004; (c) W. Thang and
D. P. Curran, Tetrahedron, 2006, 62, 11837–11865.
10 For a review on fluorous organocatalysts, see: W. Zhang and
C. Cai, Chem. Commun., 2008, 5686–5694; For other examples
of fluorous organocatalysts, see: (a) G. Pozzi, M. Cavazzini,
O. Holczknecht, S. Quici and I. Shepperson, Tetrahedron Lett.,
2004, 45, 4249–4251; (b) J. Legros, B. Crousse and D. Bonnet-
Delpon, J. Fluorine Chem., 2008, 129, 974–977; (c) D. Vuluga,
J. Legros, B. Crousse and D. Bonnet-Delpon, Chem.–Eur. J., 2010,
16, 1776–1779; (d) L. Wang, C. Cai, D. P. Curran and W. Zhang,
Synlett, 2010, 433–436; (e) T. Miura, K. Imai, M. Ina, N. Tada,
N. Imai and A. Itoh, Org. Lett., 2010, 12, 1620–1623.
11 (a) C. Rocaboy and J. A. Gladysz, Chem.–Eur. J., 2003, 9, 96–105;
(b) V. Tesevic and J. A. Gladysz, Green Chem., 2005, 7, 833–836;
(c) V. Tesevic and J. A. Gladysz, J. Org. Chem., 2006, 71,
7433–7440.
12 (a) K. Ishihara, S. Kondo and H. Yamamoto, Synlett, 2001,
1371–1374; (b) M. Wende, R. Meier and J. A. Gladysz, J. Am. Chem.
Soc., 2001, 123, 11490–11491; (c) M. Wende and J. A. Gladysz,
J. Am. Chem. Soc., 2003, 125, 5861–5872; (d) K. Mikami, Y. Mikami,
H. Matsuzawa, Y. Matsumoto, J. Nishikido, F. Yamamoto and
H. Nakajima, Tetrahedron, 2002, 58, 4015–4021; (e) J. Bayardon,
O. Holczknecht, G. Pozzi and D. Sinou, Tetrahedron: Asymmetry,
2006, 17, 1568–1572; (f) R. Kolodziuk, C. Goux-Henry and D. Sinou,
Tetrahedron: Asymmetry, 2007, 18, 2782–2786; (g) S. Goushi,
K. Funabiki, M. Ohta, K. Hatano and M. Matsui, Tetrahedron,
2007, 63, 4061–4066.
Scheme 3 Plausible mechanism of catalytic oxidation using fluorous
IBX.
This work was supported in part by Grants-in-Aid for
Scientific Research (C) (No. 22590007) from the Japan Society
for the Promotion of Science and Suzuken Memorial
Foundation.
13 A typical procedure of oxidation using fluorous organocatalyst 4 is
as follows: to a colorless solution of diphenylmethanol (6a, 100 mg,
0.543 mmol) and the organocatalyst 4 (39.3 mg, 0.054 mmol) in
MeNO2 (1.6 mL) and H2O (0.6 mL) were added Oxone (334 mg,
0.543 mmol) and Bu4NHSO4 (18.4 mg, 0.054 mmol) at room
temperature. The reaction mixture was stirred at 70 1C for 8 h,
and then cooled to room temperature. The precipitated fluorous
IBA (9) was filtered, and washed with water and ether. The
collected 9 was dried in vacuo, and was used in the next step
without further purification. The filtrate was extracted three times
with EtOAc. The EtOAc layers were combined, washed with brine,
dried over anhydrous MgSO4, and evaporated. The residue was
purified by flash column chromatography on silica gel with a 5 : 1
mixture of hexane and EtOAc to afford pure benzophenone
(7a, 86.4 mg, 87%).
Notes and references
1 M. Frigerio and M. Santagostino, Tetrahedron Lett., 1994, 35,
8019–8022.
2 (a) U. Ladziata and V. V. Zhdankin, ARKIVOC, 2006, ix, 26–58;
(b) M. Ochiai and K. Miyamoto, Eur. J. Org. Chem., 2008,
4229–4239; (c) V. V. Zhdankin and P. J. Stang, Chem. Rev.,
2008, 108, 5299–5358.
3 (a) L. B. Plumb and D. J. Harper, Chem. Eng. News, 1990, 68, 3;
´
(b) A. Ozanne, L. Pouysegu, D. Depernet, B. Francois and
S. Quideau, Org. Lett., 2003, 5, 2903–2906.
4 (a) A. P. Thottumkara and T. K. Vinod, Tetrahedron Lett., 2002,
43, 569–572; (b) J. T. Su and W. A. Goddard III, J. Am. Chem.
Soc., 2005, 127, 14146–14147; (c) R. D. Richardson, J. M. Zayed,
S. Altermann, D. Smith and T. Wirth, Angew. Chem., Int. Ed.,
2007, 46, 6529–6532; (d) J. N. Moorthy, N. Singhal and
K. Senapati, Tetrahedron Lett., 2008, 49, 80–84.
14 Fluorous IBA (9) did not have the oxidative activity. Only 5% of
benzophenone (7a) was given when using a stoichiometric amount
of 9 in the presence of Bu4NHSO4 (0.1 equiv.) in MeNO2–H2O at
70 1C for 8 h.
c
This journal is The Royal Society of Chemistry 2011
Chem. Commun., 2011, 47, 1875–1877 1877