ORGANIC
LETTERS
2003
Vol. 5, No. 8
1361-1364
Acyclic Selenoiminium Salts: Isolation,
First Structural Characterization, and
Reactions
Yuichiro Mutoh and Toshiaki Murai*
Department of Chemistry, Faculty of Engineering, Gifu UniVersity, Yanagido,
Gifu 501-1193, Japan
Received February 26, 2003
ABSTRACT
A variety of selenoiminium salts were obtained by reacting the corresponding selenoamides with methyl triflate at room temperature for 30
s. All of the salts were stable under air. The structures of the selenoiminium salts were determined by X-ray molecular analysis. An aromatic
selenoiminium salt reacted with BuLi (3 equiv) to give two types of ketones. In a reaction with LiAlH /Te, the selenoiminium salts were
4
converted to telluroamides.
Thioiminium salts, in which a sulfenyl group is attached to
the carbon atom of an iminium salt, have been extensively
studied.1 In contrast, despite the fact that the first selenium
isologues of thioiminium salts, i.e., selenoiminium salts, were
synthesized in 1966,2 the structure and reactivity of these
salts have not yet been reported, although reactions of cyclic
selenoiminium salts in which the selenium atom is located
in a five- or six-membered ring have been described.3
Recently, increasing attention has been paid to the synthesis,
structure, and reactivity of selenocarbonyl compounds.4 We
previously studied the synthesis5 and reactions6 of selenium
isologues of amides, i.e., selenoamides. For example, alky-
(1) For example, see: (a) Shiosaki, K. In ComprehensiVe Organic
Synthesis; Trost, B. M., Fleming, I., Eds.; Pergamon Press: Oxford, 1991;
Vol. 2, p 865. (b) Mukaiyama, T.; Yamaguchi, T.; Nohira, H. Bull. Chem.
Soc. Jpn. 1965, 38, 2107. (c) Mukaiyama, T.; Yamaguchi, T. Bull. Chem.
Soc. Jpn. 1966, 39, 2005. (d) Yamaguchi, T.; Inomata, K.; Mukaiyama, T.
Bull. Chem. Soc. Jpn. 1968, 41, 673. (e) Mathew, S. I.; Stansfield, F. J.
Chem. Soc., Perkin Trans. 1 1974, 540. (f) Okecha, S. A.; Stansfield, F. J.
Chem. Soc., Perkin Trans. 1 1977, 1811. (g) Shiosaki, K.; Fels, G.; Rapoport,
H. J. Org. Chem. 1981, 46, 3230. (h) Sundberg, R. J.; Walters, C. P.; Bloom,
J. D. J. Org. Chem. 1981, 46, 3730. (i) Singh, P.; Barata, M. S.; Singh, H.
J. Chem. Res., Synop. 1985, 204. (j) Takahata, H.; Yamabe, K.; Yamazaki,
T. Synthesis 1986, 1063. (k) Sauve, G.; Mansour, T. S.; Lachance, P.;
Belleau, B. Tetrahedron Lett. 1988, 29, 2295. (l) Sauve, G.; Le Berre, N.;
Zacharie, B. Tetrahedron Lett. 1988, 29, 2299. (m) Heathcock, C. H.;
Davidsen, S. K.; Mills, S. G.; Sanner, M. A. J. Org. Chem. 1992, 57, 2531.
(n) Devine, P. N.; Meyers, A. I. J. Am. Chem. Soc. 1994, 116, 2633. (o)
Marchand, P.; Fargeau-Bellassoued, M.-C.; Bellec, C.; Lhommet, G.
Synthesis 1994, 1118. (p) Mook, R. A., Jr.; Lackey, K.; Bennett, C.
Tetrahedron Lett. 1995, 36, 3969. (q) Munchhof, M. J.; Meyers, A. I. J.
Am. Chem. Soc. 1995, 117, 5399. (r) Smith, D. C.; Fuchs, P. L. J. Org.
Chem. 1995, 60, 2692. (s) Sosnicki, J. G.; Liebscher, J. Synlett 1996, 1117.
(t) May, P. J.; Bradley, M.; Harrowven, D. C.; Pallin, D. Tetrahedron Lett.
2000, 40, 1627.
(2) Jensen and Nielsen reported the synthesis of selenoiminium salts by
reacting selenoacetamide, selenobenzamide, selenoformamide, and sele-
noureas with methyl iodide: Jensen, K. A.; Nielsen, P. H. Acta Chem. Scand.
1966, 20, 597.
(3) For example, see: Quast, H.; Ivanova, S.; Peters, E.-M.; Peters, K.;
von Schnering, H. G. Liebigs Ann. 1996, 1541.
(4) (a) Wu, R.; Herna´ndez, G.; Dunlap, R. B.; Odom, J. D.; Martinez,
R. A.; Silks, L. A. Trends Org. Chem. 1998, 7, 105. (b) Litvinov, V. P.
Russ. Chem. ReV. 1999, 68, 737. (c) Murai, T.; Kato, S. In Topics in Current
Chemistry; Wirth, T., Ed.; Springer-Verlag: Berlin, 2000; Vol. 208, p 177.
(d) Boyle, P. D.; Godfrey, S. M. Coord. Chem. ReV. 2001, 223, 265.
(5) (a) Murai, T.; Ezaka, T.; Niwa, N.; Kanda, T.; Kato, S. Synlett 1996,
865. (b) Murai, T.; Ezaka, T.; Kanda, T.; Kato, S. J. Chem. Soc., Chem.
Commun. 1996, 1809. (c) Murai, T. Ezaka, T.; Ichimiya, T.; Kato, S. Synlett
1997, 775. (d) Murai, T.; Mori, T.; Kato, S. Synlett 1998, 619. (e) Murai,
T.; Niwa, N.; Ezaka, T.; Kato, S. J. Org. Chem. 1998, 63, 374. (f) Murai,
T.; Ezaka, T.; Kato, S. Bull. Chem. Soc. Jpn. 1998, 71, 1193. (g) Murai,
T.; Suzuki, A.; Ezaka, T.; Kato, S. Org. Lett. 2000, 2, 311. (h) Murai, T.;
Suzuki, A.; Kato, S. J. Chem. Soc., Perkin Trans. 1 2001, 2711. (i) Murai,
T.; Aso, H.; Kato, S. Org. Lett. 2002, 4, 1407. (j) Murai, T.; Ishizuka, M.;
Suzuki, A.; Kato, S. Tetrahedron Lett. 2003, 44, 1343.
(6) (a) Murai, T.; Ezaka, T.; Kato, S. Tetrahedron Lett. 1998, 39, 4329.
(b) Murai, T.; Mutoh, Y.; Kato, S. Org. Lett. 2001, 3, 1993.
10.1021/ol034334f CCC: $25.00 © 2003 American Chemical Society
Published on Web 03/28/2003