J. N. Moorthy et al. / Tetrahedron Letters 49 (2008) 80–84
83
R1
HO
K. W.; Kranich, R.; Vega, J. A. J. Am. Chem. Soc. 2002,
124, 2233; (j) Nicolaou, K. C.; Montagnon, T.; Baran, P.
S.; Zhong, Y.-L. J. Am. Chem. Soc. 2002, 124, 2245; (k)
Nicolaou, K. C.; Montagnon, T.; Baran, P. S. Angew.
Chem., Int. Ed. 2002, 41, 993; (l) Nicolaou, K. C.; Gray,
D. L. F.; Montagnon, T.; Scott, T. H. Angew. Chem., Int.
Ed. 2002, 41, 996; (m) Nicolaou, K. C.; Mathison, C. J.
N.; Montagnon, T. Angew. Chem., Int. Ed. 2003, 42, 4077;
(n) Nicolaou, K. C.; Mathison, C. J. N.; Montagnon, T. J.
Am. Chem. Soc. 2004, 126, 5192; (o) Ngouansavanh, T.;
Zhu, J. Angew. Chem., Int. Ed. 2006, 45, 3495; (p) Kirsch,
S. F. J. Org. Chem. 2005, 70, 10210; (q) Crone, B.; Kirsch,
S. F. Chem. Commun. 2006, 764; (r) Ngouansavanh, T.;
Zhu, J. Angew. Chem., Int. Ed. 2006, 45, 3495; (s) Arote,
N. D.; Bhalerao, D. S.; Akamanchi, K. G. Tetrahedron
Lett. 2007, 47, 3651.
R2
HO
I
Me
S
Me
O
I
O
S
O
+
R2
O
R1
O
O
O
CH3
O
CH3
SET
Me
HO
I
OH
I
O
Me
O
O
+
S
S
R1
R2
R1
R2
O
+
O
O
O
O
CH3
CH3
Scheme 2. A plausible mechanism for oxidation of sulfides to
2. Plumb, B.; Harper, D. J. Chem. Eng. News 1990, 3.
3. (a) Gougoutas, J. Z. Cryst. Struct. Commun. 1981, 10, 489;
(b) Stevenson, P. J.; Treacy, A. B.; Nieuwenhuyzen, M.
J. Chem. Soc., Perkin Trans. 2 1997, 589.
sulfoxides.
In summary, we have shown that a variety of alcohols
are oxidized in a facile manner to the corresponding
carbonyl compounds at rt with a modified o-methyl-
substituted IBX; we believe that limited solubility of
Me-IBX at room temperature in common organic
solvents in conjunction with theoretically predicted
hypervalent twisting-promoted rate enhancement11
augment the conversion of alcohols to the correspond-
ing carbonyl compounds. To the best of our knowledge,
Me-IBX constitutes the first modified analog of IBX that
oxidizes alcohols in common organic solvents at rt.
Also, the reagent is efficient for the selective oxidation
of sulfides to sulfoxides. Given its facile synthetic
accessibility from a cheap starting material, Me-IBX
may constitute a stable equivalent of the DMP reagent
for oxidations.
4. Most of these modified analogs of IBX work efficiently for
reactive benzylic alcohols. In contrast, the oxidation of
aliphatic alcohols occurs over long durations.
5. Dess, D. B.; Martin, J. C. J. Am. Chem. Soc. 1991, 113,
7277.
6. Thottumkara, A. P.; Vinod, T. K. Tetrahedron Lett. 2002,
41, 569.
7. (a) Zhdankin, V. V. Curr. Org. Synth. 2005, 2, 121; (b)
Zhdankin, V. V.; Smart, J. T.; Zhao, P.; Kiprof, P.
Tetrahedron Lett. 2000, 41, 5299; (c) Zhdankin, V. V.;
Koposov, A. Y.; Netzel, B. C.; Yashin, N. V.; Rempel, B.
P.; Ferguson, M. J.; Tykwinski, R. R. Angew. Chem., Int.
Ed. 2003, 42, 2194; (d) Zhdankin, V. V.; Litvinov, D. N.;
Koposov, A. Y.; Ferguson, M. J.; McDonald, R.; Tyk-
winski, R. R. . Chem. Commun. 2004, 106; (e) Zhdankin,
V. V.; Koposov, A. Y.; Litvinov, D. N.; Ferguson, M. J.;
McDonald, R.; Luu, T.; Tykwinski, R. R. J. Org. Chem.
2005, 70, 6484; (f) Koposov, A. Y.; Zhdankin, V. V.
Synthesis 2005, 22; (g) Koposov, A. Y.; Karimov, R. R.;
Geraskin, I. M.; Nemykin, V. N.; Zhdankin, V. V. Org.
Lett. 2006, 71, 8452.
Supplementary data
8. (a) Ozanne, A.; Pouysegu, L.; Depernet, D.; Francois, B.;
Quideau, S. Org. Lett. 2003, 5, 2903; (b) Ozanne, A.;
Quideau, S. Tetrahedron Lett. 2006, 47, 5869.
9. More, J. D.; Finney, N. S. Org. Lett. 2002, 4, 3001.
10. Moorthy, J. N.; Singhal, N.; Senapati, K. Org. Biomol.
Chem. 2007, 5, 767, and references therein.
Supplementary data associated with this article can be
11. Su, J. T.; Goddard, W. A., III. J. Am. Chem. Soc. 2005,
127, 14146.
Acknowledgements
12. Shukla, V. G.; Salgaonkar, P. D.; Akamanchi, K. G. J.
Org. Chem. 2003, 68, 5422.
We thank the Department of Science and Technology,
India for the financial support. N.S. is grateful to CSIR,
India for a senior research fellowship.
13. Preparation of Me-IBX. To a solution of 2-iodo-3-methyl-
5-methoxybenzoic acid (4.2 g, 14.4 mmol) in 50.0 mL of
H2O was added 13.3 g (21.6 mmol) of oxone. The resul-
tant mixture was stirred at 70 °C for 6.0 h. The solid
precipitate was filtered and dried under vacuum to afford
3.73 g (80%) of a hypervalent iodine compound which was
confirmed by spectroscopic techniques as a modified Me-
References and notes
1. (a) Stang, P. J.; Zhdankin, V. V. Chem. Rev. 2002, 102,
2523; (b) Ladziata, U.; Zhdankin, V. V. ARKIVOC 2006,
9, 26; (c) Frigerio, M.; Santagostino, M. Tetrahedron Lett.
1994, 35, 8019; (d) Nicolaou, K. C.; Zhong, Y.-L.; Baran,
P. S. J. Am. Chem. Soc. 2000, 122, 7596; (e) Nicolaou, K.
C.; Baran, P. S.; Zhong, Y.-L. Angew. Chem., Int. Ed.
2000, 39, 625; (f) Nicolaou, K. C.; Baran, P. S.; Zhong,
Y.-L. J. Am. Chem. Soc. 2001, 123, 3183; (g) Nicolaou, P.
S.; Baran, P. S. Angew. Chem., Int. Ed. 2002, 41, 2678; (h)
Nicolaou, K. C.; Baran, P. S.; Remo, K.; Zhong, Y.-Li.;
Sugita, K.; Zou, N. Angew. Chem., Int. Ed. 2001, 40, 202;
(i) Nicolaou, K. C.; Baran, P. S.; Zhong, Y.-L.; Barluenga,
1
IBX; IR (KBr) cmꢁ1 3462, 1665, 733; H NMR (DMSO-
d6, 400 MHz) d 2.72 (s, 3H), 3.86 (s, 3H), 7.14 (s, 1H), 7.35
(s, 1H); 13C NMR (CDCl3 + DMSO-d6, 100 MHz) d 20.0,
55.9, 112.8, 123.3, 135.8, 138.2, 141.4, 161.8, 167.4; ESI-
MS (MꢁH) Calcd for C9H8IO5 322.9417; found 322.9416.
14. General procedure for oxidation of alcohols with Me-IBX in
acetone.16 Me-IBX (1.5 equiv) in 10.0 mL of acetone was
stirred for 5–10 min, and to this mixture 1–2 mmol of the
alcohol was introduced. The reaction mixture was stirred
for appropriate duration (see Table 1). The progress of the
reaction was monitored by TLC analysis. After comple-