476
J. V. Comasseto et al. / Tetrahedron Letters 45 (2004) 473–476
6. (a) Yadav, J. S.; Nanda, S.; Reddy, P. T.; Rao, A. B. J. Org.
reaction: The reactions using 100 mg of the organochal-
cogeno ketones 3 in ethanol (2.5 mL) were performed in
1 L Erlenmeyer flasks containing freshly cut carrot roots
(50 g), water (500 mL) at 32 ꢁC on an orbital shaker
(170 rpm). After the appropriate conversion time (Table
1), the mixture was filtered off and the carrot suspension
was washed with ethyl acetate (100 mL). The aqueous
phase was extracted with ethyl acetate (5 ꢁ 100 mL). The
organic phases were combined and dried over MgSO4. The
solvent was removed in vacuum and the residue was
purified on a silica gel column using a mixture of hexane
and ethyl acetate (4:1) as eluent to afford compounds 4.
Chem. 2002, 67, 3900, and references cited therein; (b)
Yadav, J. S.; Reddy, P. T.; Nanda, S.; Rao, A. B.
Tetrahedron: Asymmetry 2001, 12, 3381; (c) Maczka, W.
A.; Mironowicz, A. Tetrahedron: Asymmetry 2002, 13,
2299.
7. (a) Ferraboschi, P.; Grisenti, P.; Santaniello, E. Synlett
1990, 545; (b) Holland, H. I.; Carter, I. M. Bioorg. Chem.
1983, 12, 1; (c) Latham, J. A.; Branchaud, B. P.; Chen, Y.
C. J.; Walsh, C. J. Chem. Soc., Chem. Commun. 1986, 7,
528; (d) Branchaud, B. P.; Walsh, C. T. J. Am. Chem. Soc.
1985, 107, 2153.
8. (a) Silks, L. A.; Dunlap, R. B.; Odom, J. D. J. Am. Chem.
Soc. 1990, 112, 4979; (b) Silks, L. A.; Peng, J.; Odom, J. D.;
Dunlap, R. B. J. Org. Chem. 1991, 56, 6733; (c) Heden-
strom, E.; Nguyen, B.-V.; Silks, L. A. Tetrahedron:
Asymmetry 2002, 13, 835; For a recent example, see:
Menezes, P. H.; Gonßcalves, S. M. C.; Hallwass, F.; Silva,
R. O.; Bieber, L. W.; Simas, A. M. Org. Lett. 2003, 5, 1601.
9. For a review, see: Pu, L.; Yu, H.-B. Chem. Rev. 2001, 101,
757.
10. For a review, see: Luh, T.-Y.; Ni, Z.-J. Synthesis 1990, 89;
For a recent example, see: Alphonse, F.-A.; Suzenet, F.;
Keromnes, A.; Lebret, B.; Guillaumet, G. Org. Lett. 2003,
5, 803.
1-(Organylchalcogeno-phenyl)-ethanols 4b: oil, yield ¼
26
26
D
86%, ½aꢂ )28.6ꢁ (c 1.5, CHCl3), ee ¼ 99%; 4c: oil,
26
yield ¼ 74%, ½aꢂ )35.2ꢁ (c 1.25, CHCl3), ee ¼ 99%;
26
D
4e: oil, yield ¼ 60%, ½aꢂ )14.2ꢁ (c 2.4, CHCl3), ee ¼
23
D
99%; 4f: oil, yield ¼ 52%, ½aꢂ )12.1ꢁ (c 1.5, CHCl3),
23
D
ee ¼ 99%; 4h: oil, yield ¼ 66%, ½aꢂ )41.1ꢁ (c 0.71, CHCl3),
D
ee ¼ 99%; 4i: oil, yield
CHCl3), ee ¼ 99%.
¼
60%, ½aꢂ )47.3ꢁ (c 0.57,
D
18. The (S)-3- and (S)-4-bromo-a-methylbenzyl alcohols were
obtained by enzymatic kinetic resolution of the appropri-
ate racemic mixture of meta- and para-bromo-a-methyl-
benzyl alcohols mediated by Novozym 435 (CAL-B) in
tert-butyl methyl ether as the solvent and vinyl acetate as
the acetyl donor. Further reaction of these chiral bromo
precursors was carried out with t-BuLi followed by
addition of the appropriate elemental chalcogen and
methyl iodide or diphenyl diselenide to insert the orga-
nochalcogeno group. Andrade, L. H.; Omori, A. T.;
Porto, A. L. M.; Comasseto, J. V., in press.
11. For an example, see: Okamura, H.; Miura, M.; Kosugi,
K.; Takei, H. Tetrahedron Lett. 1980, 21, 87.
12. The coupling of aromatic selenides and tellurides with
alkynes under palladium catalysis is under investigation in
our group, in analogy with similar reactions involving
vinylic derivatives of these elements. For the coupling of
sp2-derivatives of tellurium with acetylenes mediated by
Pd, see: Zeni, G.; Comasseto, J. V. Tetrahedron Lett. 1999,
40, 4619; For a review, see: Zeni, G.; Braga, A. L.; Stefani,
H. A. Acc. Chem. Res. 2003, 36, 731; For similar reactions
with vinylic selenides, see: Comasseto, J. V.; Ling, L. W.;
Petragnani, N.; Stefani, H. A. Synthesis 1997, 373.
13. Feugeas, G. Bull. Soc. Chim. Fr. 1963, 11, 2573.
14. Wirth, T.; Fragale, G. Chem. Eur. J. 1997, 3, 1894.
15. All the new compounds synthesized were fully character-
ized. Selected spectral data: Compound 3c: mp ¼ 71 ꢁC. IR
(KBr) cmꢀ1: 2996, 2959, 2922, 1669, 1564, 1424, 1394,
19. Prelog, V. Pure Appl. Chem. 1964, 9, 119.
ꢀ
20. For examples, see: (a) Cordova, A.; Janda, K. D. J. Org.
Chem. 2001, 66, 1906; (b) Zhang, Y.; Yuan, C.; Li, Z.
Tetrahedron 2002, 58, 2973; (c) Xu, D.; Li, Z.; Ma, S.
Tetrahedron Lett. 2003, 44, 6343.
21. General procedure: The enzyme (50 mg) was added to a
solution of (RS)-ortho-organochalcogeno-a-methylbenzyl
alcohols 4a, 4d or 4g (0.20 mmol) and vinyl acetate
(0.25 mL) in hexane (3 mL). The resulting mixture was
stirred on an orbital shaker (170 rpm) at 32 ꢁC. After 24 h
the enzyme was filtered off and washed with dichlorome-
thane (20 mL). The solvent was removed in vacuum and
the residue was purified on a silica gel column using a
mixture of hexane and ethyl acetate (4:1) as eluent to afford
1
1356, 1273, 1184, 1081, 955, 911, 812, 745, 589. H NMR
(300 MHz) d (ppm): 7.85 (d, J ¼ 8:5 Hz, 2H), 7.45 (d,
J ¼ 8:5 Hz, 2H), 2.59 (s, 3H), 2.43 (s, 3H). 13C NMR
(75 MHz) d (ppm): 197.3, 140.8, 134.4, 128.6, 128.5, 26.4,
6.7. MS: m=z (relative intensity) 214 (Mþ, 74), 212 (37),
199 (100), 184 (21), 171 (15), 156 (14), 130 (3), 117 (6), 91
(61), 76 (13), 63 (13), 43 (50). Found: C, 50.75; H, 4.58.
Calcd for C9H10OSe: C, 50.72; H, 4.73.
the alcohols 4 and their acetates 5 (Table 2). Compounds
25
D
4a: oil, yield ¼ 45%, ½aꢂ )42.4ꢁ (c 2.0, CHCl3), ee ¼
25
25
D
99%; 4d: oil, yield ¼ 45%, ½aꢂ )63.5ꢁ (c 1.37, CHCl3),
23
ee ¼ 99%; 4g: oil, yield ¼ 48%, ½aꢂ )68.3ꢁ (c 1.58, CHCl3),
23
D
ee ¼ 99%; 5a: oil, yield ¼ 50%, ½aꢂ +44.7ꢁ (c 2.35,
23
D
16. All the new compounds synthesized were fully character-
:
CHCl3), ee ¼ 97%; 5d: oil, yield ¼ 52%, ½aꢂ +43.2ꢁ (c
D
ized. Selected spectral data: Compound 4c: IR (film) cmꢀ1
3362, 2971, 2927, 2871, 1721, 1595, 1493, 1419, 1368, 1273,
2.33, CHCl3), ee ¼ 88%; 5g: oil, yield ¼ 49%, ½aꢂ +41.3ꢁ
D
(c 1.0, CHCl3), ee ¼ 98%. The chiral standards (S)-4a, (S)-
4d and (S)-4g were prepared from (S)-1-phenylethanol
using ortho-lithiation method with n-BuLi and TMEDA
followed by addition of the appropriate elemental chalco-
gen and methyl iodide or diphenyl diselenide to insert the
organochalcogeno group. Andrade, L. H.; Omori, A. T.;
Porto, A. L. M.; Comasseto, J. V.; Cunha, R. L. O. R.
Unpublished results.
1
1113, 1087, 900, 791, 581. H NMR (500 MHz) d (ppm):
7.40 (d, J ¼ 8:3 Hz, 2H), 7.26 (d, J ¼ 8:0 Hz, 2H), 4.85 (q,
J ¼ 6:3 Hz, 1H), 2.34 (s, 3H), 1.47 (d, J ¼ 6:3 Hz, 3H),
1.30 (s, 1H). 13C NMR (125 MHz) d (ppm): 143.9, 130.5,
130.4, 126.1, 70.0, 25.1, 7.3. MS: m=z (relative intensity)
216 (Mþ, 57), 214 (29), 201 (71), 183 (5), 173 (10), 157 (44),
153 (10), 121 (4), 100 (20), 91 (28), 78 (56), 51 (22), 43
(100). Found: C, 50.51; H, 5.86. Calcd for C9H12OSe: C,
50.24; H, 5.62.
22. Chen, C.-S.; Fujimoto, Y.; Girdaukas, G.; Sih, C. J. J.
Am. Chem. Soc. 1982, 104, 7294.
17. To increase the contact of the substrate with the biocat-
alyst, the external layer was removed and the rest was cut
into small thin slices (5 mm). Preparative-scale reduction
23. Preliminary results show Dd up to 2.4 ppm in the
77Se NMR spectra for substituted esters prepared
with 4d.