V.A. Soloshonok, M. Yasumoto / Journal of Fluorine Chemistry 128 (2007) 170–173
173
gies, Materials and Biological Applications, ACS Symposium Series
#949, Oxford University Press, 2006.
temperature. After dissolving the acid by heating the solution at
80 8C, the solution was cooled down to room temperature to
precipitate the crystals. Five consecutive crystallizations gave
the L-tartaric acid salt with amine 1 of at least 99.5% ee. (0.52 g,
1.59 mmol). The salt was decompoused with 3N NaOH, and
amine 1 was extracted with ethyl acetate. The solvent was
evaporated under reduced pressure to give amine 1 (0.26 g,
1.51 mmol, 99.5% ee.).
[3] (a) V.A. Soloshonok, T. Ono, J. Org. Chem. 62 (1997) 3030;
(b) B. Torok, G.K.S. Prakash, Adv. Synth. Catal. 345 (2003) 165;
(c) F. Gosselin, P.D. O’Shea, S. Roy, R.A. Reamer, C. Chen, R.P. Volante,
Org. Lett. 7 (2005) 355;
(d) F. Huguenot, T. Brigaud, J. Org. Chem. 71 (2006) 7075;
(e) C. Lauzon, A.B. Charette, Org. Lett. 8 (2006) 2743;
(f) G.K.S. Prakash, R. Mogi, G.A. Olah, Org. Lett. 8 (2006) 3589.
[4] For full papers on biomimetic transamination of fluorinated carbonyl
compounds, see:
3.3. Determination of the enantiomeric purity of the
amine 1
(a) T. Ono, V.P. Kukhar, V.A. Soloshonok, J. Org. Chem. 61 (1996)
6563;
(b) V.A. Soloshonok, T. Ono, Tetrahedron 52 (1996) 14701;
(c) V.A. Soloshonok, V.P. Kukhar, Tetrahedron 52 (1996) 6953;
(d) V.A. Soloshonok, V.P. Kukhar, Tetrahedron 53 (1997) 8307;
(e) V.A. Soloshonok, I.V. Soloshonok, V.P. Kukhar, V.K. Svedas, J. Org.
Chem. 63 (1998) 1878.
Imine 5 (0.13 g, 0.494 mmol) was stirred with 3N HCl
(1.5 mL) and diethyl ether (1.0 mL) for 1 day at rt. After
separation, 3N NaOH aq. was added to the aqueous layer until
the solution became pH-14. After extraction with ethyl acetate,
the ethyl acetate was removed under reduced pressure to give
amine 1. To the solution of triethylamine and amine 1 in
dichloromethane, 3,5-dinitorobenzoyl chloride was added. The
solution was stirred for 3 h at room temperature and the
resulting mixture was washed with water. The organic layer was
evaporated under reduced pressure. Thus, obtained product was
used for determination of the enantiomeric purity. Since the
compounds of this type, with trifluoromethyl group directly
bonded to the stereogenic center, are prone to the enantiomer
self-disproportionation effect [11], the corresponding 3,5-
dinitorobenzoyl derivative [3a] of amine 1 was not isolated and
the crude product was used for HPLC analyses.
[5] For recent advances, see:
(a) V.A. Soloshonok, M. Yasumoto, J. Fluor. Chem. 127 (2006) 889;
(b) V.A. Soloshonok, H. Ohkura, M. Yasumoto, J. Fluor. Chem. 127
(2006) 924;
(c) V.A. Soloshonok, H. Ohkura, M. Yasumoto, J. Fluor. Chem. 127
(2006) 930;
(d) V.A. Soloshonok, H. Ohkura, K. Uneyama, Tetrahedron Lett. 43
(2002) 5449.
[6] V.A. Soloshonok, A.G. Kirilenko, S.V. Galushko, V.P. Kukhar, Tetrahe-
dron Lett. 35 (1994) 5063.
[7] S. Diezi, A. Szabo, T. Mallat, A. Baiker, Tetahedron Asymmetry 14 (2003)
2573–2577.
[8] D.O. Berbasov, I.D. Ojemaye, V.A. Soloshonok, J. Fluor. Chem. 125
(2004) 603.
[9] Y. Wang, H.S. Mosher, Tetrahedron Lett. 32 (1991) 987–990.
[10] For our discussions on this subject see the following papers and references
in them:
Column: SUMICHIRAL OA-4500; eluent: n-hexane/dichlor-
omethane/ethanol = 60/30/10; retention times: 14.7 min for (S)
and 16.1 min for (R).
(a) V.A. Soloshonok, V.P. Kukhar, S.V. Galushko, N.Y. Svistunova, D.V.
Avilov, N.A. Kuzmina, N.I. Raevski, Y.T. Struchkov, A.P. Pisarevsky, Y.N.
Belokon, J. Chem. Soc. Perkin. Trans. 1 (1993) 3143–3155;
(b) V.A. Soloshonok, T. Hayashi, K. Ishikawa, N. Nagashima, Tetrahe-
dron Lett. 35 (1994) 1055–1058;
Acknowledgements
(c) V.A. Soloshonok, D.V. Avilov, V.P. Kukhar, Tetrahedron 52 (1996)
12433–12442;
This work was supported by Department of Chemistry and
Biochemistry, University of Oklahoma. The authors gratefully
acknowledge generous financial support from Central Glass
Company (Tokyo, Japan) and Ajinomoto Company (Tokyo,
Japan).
(d) V.A. Soloshonok, A.D. Kacharov, D.V. Avilov, T. Hayashi, Tetrahe-
dron Lett. 37 (1996) 7845–7848;
(e) V.A. Soloshonok, A.D. Kacharov, D.V. Avilov, K. Ishikawa, N.
Nagashima, T. Hayashi, J. Org. Chem. 62 (1997) 3470–3479;
(f) M. Kanai, M. Yasumoto, Y. Kuriyama, K. Inomiya, Y. Katsuhara, K.
Higashiyama, A. Ishii, Org. Lett. 5 (2003) 1007–1010.
[11] (a) V.A. Soloshonok, Angew. Chem. In. Ed. Engl. 45 (2006) 766–
769;
References
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