PAPER
2-(Trimethylsilyl)ethyl Sulfoxides as a Convenient Source of Sulfenate Anions
1323
(4) (a) Maezaki, N.; Yagi, S.; Ohsawa, S.; Ohishi, H.; Tanaka,
T. Tetrahedron 2003, 59, 9895. (b) Maezaki, N.; Yagi, S.;
233. For deprotection of selenothioic acid S-esters:
(i) Murai, T.; Kamoto, T.; Kato, S. J. Am. Chem. Soc. 2000,
122, 9850. (j) Niyomura, O.; Sakai, K.; Murai, T.; Kato, S.;
Yamaguchi, S.; Tamao, K. Chem. Lett. 2001, 968.
(k) Kimura, T.; Murai, T.; Miwa, A.; Kurachi, D.;
Yoshikawa, H.; Kato, S. J. Org. Chem. 2005, 70, 5611. For
deprotection of phosphinoselenothioic acid S-esters:
(l) Kimura, T.; Murai, T. Chem. Commun. 2005, 4077.
(12) (a) Bernhard, W.; Fleming, I. J. Organomet. Chem. 1984,
271, 281. (b) Jones, S. L.; Stirling, C. J. M. J. Chem. Soc.,
Chem. Commun. 1988, 1153.
Yoshigami, R.; Maeda, J.; Suzuki, T.; Ohsawa, S.;
Tsukamoto, K.; Tanaka, T. J. Org. Chem. 2003, 68, 5550.
(c) Maezaki, N.; Yagi, S.; Maeda, J.; Yoshigami, R.; Tanaka,
T. Heterocycles 2004, 62, 263.
(5) O’Donnell, J. S.; Schwan, A. L. Tetrahedron Lett. 2003, 44,
6293.
(6) (a) Caupène, C.; Boudou, C.; Perrio, S.; Metzner, P. J. Org.
Chem. 2005, 70, 2812. (b) Maitro, G.; Prestat, G.; Madec,
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(7) (a) Oida, T.; Ohnishi, A.; Shimamaki, T.; Hayashi, Y.;
Tanimoto, S. Bull. Chem. Soc. Jpn. 1991, 64, 702. (b)Oida,
T.; Nakamura, M.; Takashima, Y.; Hayashi, Y. Bull. Inst.
Chem. Res., Kyoto Univ. 1992, 70, 295.
(8) Benzenesulfenic acid 2-(trimethylsilyl)ethyl ester was
prepared by reaction of benzenesulfenyl chloride with 2-
(trimethylsilyl)ethyl alcohol. By comparison, the analogous
sulfoxides are readily available from commercial
(13) Wagner, M.; Kunz, H. Synlett 2000, 400.
(14) (a) Gornowicz, G. A.; Ryan, J. W.; Speier, J. L. J. Org.
Chem. 1968, 33, 2918. (b) Mahadevan, A.; Li, C.; Fuchs, P.
L. Synth. Commun. 1994, 24, 3099. (c) Menichetti, S.;
Stirling, C. J. M. J. Chem. Soc., Perkin Trans. 1 1996, 1511.
(15) (a) Bégué, J.-P.; Bonnet-Delpon, D.; Crousse, B. Synlett
2004, 18. (b) Ravikumar, K. S.; Kesavan, V.; Crousse, B.;
Bonnet-Delpon, D.; Bégué, J.-P. Org. Synth., Vol. 80; John
Wiley & Sons: London, 2003, 184.
(16) Methyl sulfinate 4 was prepared by oxidative fragmentation
of sulfoxide 1g (R1 = t-Bu) using SO2Cl2 to give 2-
(trimethylsilyl)ethanesulfinyl chloride,9f followed by
treatment with MeOH in the presence of Et3N.
compounds according to: (a) Schwan, A. L.; Pippert, M. F.
Tetrahedron: Asymmetry 1995, 6, 131. (b) Schwan, A. L.;
Brillon, D.; Dufault, R. Can. J. Chem. 1994, 72, 325.
(9) The reactivity of more sophisticated b-silyl sulfoxides with
TBAF has previously been investigated by the group of
Toru, but their attention was focused on the alkene product:
(a) Nakamura, S.; Watanabe, Y.; Toru, T. J. Chem. Soc.,
Perkin Trans. 1 1999, 3403. (b) Nakamura, S.; Takemoto,
H.; Ueno, Y.; Toru, T.; Kakumoto, T.; Hagiwara, T. J. Org.
Chem. 2000, 65, 469. (c) Nakamura, S.; Uchiyama, Y.;
Ishikawa, S.; Fukinbara, R.; Watanabe, Y.; Toru, T.
Tetrahedron Lett. 2002, 43, 2381. (d) Nakamura, S.;
Kusuda, S.; Kawamura, K.; Toru, T. J. Org. Chem. 2002, 67,
640. (e) Nakamura, S.; Nakayama, J.-i.; Toru, T. J. Org.
Chem. 2003, 68, 5766. Schwan also described a fluoride
free deprotection of simple 2-(trimethylsilyl)ethyl
sulfoxides by treatment with thionyl chloride to afford
sulfinyl chlorides: (f) Schwan, A. L.; Strickler, R. R.; Dunn-
Dufault, R.; Brillon, D. Eur. J. Org. Chem. 2001, 1643.
(10) (a) Huttunen, K. M.; Kumpalainen, H.; Leppänen, J.; Rautio,
J.; Järvinen, T.; Vepsäläinen, J. Synlett 2006, 701.
(b) Fustero, S.; García Sancho, A.; Chiva, G.; Sanz-Cervera,
J. F.; del Pozo, C.; Aceña, J. L. J. Org. Chem. 2006, 71,
3299. (c) Grecian, S. A.; Hadida, S.; Warren, S. D.
Tetrahedron Lett. 2005, 46, 4683. (d) Bottaro, J. C.;
Penwell, P. E.; Schmitt, R. J. J. Am. Chem. Soc. 1997, 119,
9405. (e) Varaprasad, C. V. N. S.; Johnson, F. Tetrahedron
Lett. 2005, 46, 2163. (f) Thakkalapally, A.; Benin, V.
Tetrahedron 2005, 61, 4939.
(11) For a review concerning the 2-(trimethylsilyl)ethyl group in
synthesis, see: (a) Chambert, S.; Désiré, J.; Décout, J.-L.
Synthesis 2002, 2319. See also for deprotection of sulfides:
(b) Flatt, A. K.; Dirk, S. M.; Henderson, J. C.; Shen, D. E.;
Su, J.; Reed, M. A.; Tour, J. M. Tetrahedron 2003, 59, 8555.
(c) Chatterji, T.; Kizil, M.; Keerthi, K.; Chowdhury, G.;
Pospísil, T.; Gates, K. S. J. Am. Chem. Soc. 2003, 125,
4996. (d) Hamm, M. L.; Cholera, R.; Hoey, C. L.; Gill, T. J.
Org. Lett. 2004, 6, 3817. (e) Pollack, S. K.; Naciri, J.;
Mastrangelo, J.; Patterson, C. H.; Torres, J.; Moore, M.;
Shashidhar, R.; Kushmerick, J. G. Langmuir 2004, 20,
1838. (f) Morales, G. M.; Jiang, P.; Yuan, S.; Lee, Y.;
Sanchez, A.; You, W.; Yu, L. J. Am. Chem. Soc. 2005, 127,
10456. For deprotection of sulfones: (g) Lai, M.-t.; Oh, E.;
Shih, Y.; Liu, H.-w. J. Org. Chem. 1992, 57, 2471.
(h) Palmer, J. T.; Fuchs, P. L. Synth. Commun. 1988, 18,
(17) Silicon contains 4.7% 29Si isotope with nuclear spin I = ½
and a gyromagnetic ratio g = –(2p)8.46 × 106 s–1 T–1, see for
example: Fortis, F.; Barbe, B.; Pétraud, M.; Picard, J.-P.
Chem. Commun. 1999, 527.
(18) Similar chemical shifts were observed either in CDCl3 or
THF-d8.
(19) Crystal structure determination of 1b: Single crystals of
sulfoxide 1b suitable for X-ray crystallographic analysis
were obtained by slow diffusion of pentane in CH2Cl2 soln.
X-ray diffraction experiments for monocrystal of 1b were
performed at 150 K with graphite–monochromatized MoKa
radiation on a Bruker-Nonius Kappa CCD area detector
diffractometer. Formula C11H17BrOSSi, Mr 305.31, crystal
system triclinic, space group P1, a = 6.5653 (3) Å,
b = 10.1206 (4) Å, c = 11.8654 (5) Å, a = 66.082 (2)°,
b = 78.256 (3)°, g = 80.455 (3)°, V = 702.54 (5) Å3, Z = 2,
density calcd = 1.443 g/cm3, m = 3.135 cm–1, R = 0.0386,
wR = 0.0997. Selected bond lengths (Å) and angles(deg):
Br1–C1 1.8912 (14), S1–O1 1.4930 (13), S1–C4 1.7924
(13), S1–C7 1.8248 (14), Si1–C8 1.8792 (14), Si1–C9
1.8512 (18), Si1–C10 1.862 (2), Si1–C11 1.862 (2), C7–C8
1.512 (2), O1–S1–C4 106.27 (7), O1–S1–C7 106.60 (7),
C4–S1–C7 97.78 (6), C11–Si1–C8 106.90 (8), C9–Si1–C8
109.56 (9), C10–Si1–C8 110.30 (10). Program(s)used to
solve structure: SHELXS97. Program(s)used to refine
structure: SHELXL97. Software used to prepare material for
publication: SHELXL97. Crystallographic data for
compound 1b have been deposited at the Cambridge
Crystallographic Data Centre, CCDC No 629340. Copies of
this information may be obtained free of charge from The
Director, CCDC, 12 Union Road, Cambridge, CB2 1EZ,
UK; +44 (1223)336408; E-mail: deposit@ccdc.cam.ac.uk or
(20) An intramolecular coordination between the oxygen atom of
the sulfoxide group and the silicon center was previously
detected at low temperature with the analogous electron
deficient trifluorosilyl derivatives: Pestunovich, V. A.;
Larin, M. F.; Sorokin, M. S.; Albanov, A. I.; Voronkov, M.
G. J. Organomet. Chem. 1985, 280, C17.
(21) Similar structural effects involving the 2-(trimethyl-
silyl)ethyl system have already been mentioned with
carboxylate and sulfenate esters: Green, A. J.; Issa, W.;
White, J. M. Aust. J. Chem. 1997, 50, 927.
Synthesis 2007, No. 9, 1315–1324 © Thieme Stuttgart · New York