2626
S. B. Tsogoeva, S. B. Jagtap
LETTER
(2) (a) Iyer, M. S.; Gigstad, K. M.; Namdev, N. D.; Lipton, M.
J. Am. Chem. Soc. 1996, 118, 4910. (b) Miller, S. J.;
Copeland, G. T.; Papaioannou, N.; Horstmann, T. E.; Ruel,
E. M. J. Am. Chem. Soc. 1998, 120, 1629. (c) Vachal, P.;
Jacobsen, E. N. J. Am. Chem. Soc. 2002, 124, 10012.
(d) Tang, Z.; Jiang, F.; Yu, L.-T.; Cui, X.; Gong, L.-Z.; Mi,
A.-Q.; Jiang, Y.-Z.; Wu, Y.-D. J. Am. Chem. Soc. 2003, 125,
5262. (e) Martin, H. J.; List, B. Synlett 2003, 1901.
(f) Kofoed, J.; Nielsen, J.; Reymond, J.-L. Bioorg. Med.
Chem. Lett. 2003, 13, 2445. (g) Tsogoeva, S. B.; Jagtap, S.
B.; Ardemasova, Z. A.; Kalikhevich, V. N. Eur. J. Org.
Chem. 2004, 4014.
Table 2 Michael Addition Catalyzed by Dipeptide 1 in the Presence
of (1R,2R)-(+)-1,2-Diphenylethylenediamine 7 as Additive (in DMF)
Entry
1 (mol%)
7 (mol%)
30
Yield (%)a ee (%, R)b
1
2
3
4
5
15
15
21
62
86
41
39
42
61
75
91
91
100
30
30
50
100
100
100
(3) Reviews: (a) Dalko, P. I.; Moisan, L. Angew. Chem. Int. Ed.
2001, 40, 3726; Angew. Chem. 2001, 113, 3840.
a Isolated yields after chromatography.
(b) Gröger, H.; Wilken, J. Angew. Chem Int. Ed. 2001, 40,
529; Angew. Chem. 2001, 113, 545. (c) Jarvo, E. R.; Miller,
S. J. Tetrahedron 2002, 58, 2481. (d) Groeger, H.; Wilken,
J.; Berkessel, A. In Organic Synthesis Highlights V;
Schmalz, H.-G.; Wirth, T., Eds.; VCH: Weinheim, 2003,
178.
b Enantioselectivities were determined by chiral HPLC analysis
(Daicel Chiralpak AS) in comparison with authentic racemic
material.
(4) (a) Hajos, Z. G.; Parrish, D. R. J. Org. Chem. 1974, 39,
1615. (b) Eder, U.; Sauer, G.; Wiechert, R. Angew. Chem.,
Int. Ed. Engl. 1971, 10, 496; Angew. Chem. 1971, 83, 492.
(c) Agami, C.; Meynier, F.; Puchot, C.; Guilhem, J.; Pascard,
C. Tetrahedron 1984, 40, 1031.
In addition we expect the further improved catalytic
system to become useful for a variety of other C–C, C–N,
C–S bond formation reactions and some other important
transformations.
(5) (a) Danishefsky, S.; Cain, P. J. Am. Chem. Soc. 1976, 98,
4975. (b) Hagiwara, H.; Uda, H. J. Org. Chem. 1988, 53,
2308.
Acknowledgment
(6) (a) Rossiter, B. E.; Swingle, N. M. Chem. Rev. 1992, 92,
771. (b) Yamaguchi, M.; Shiraishi, T.; Hirama, M. J. Org.
Chem. 1996, 61, 3520. (c) Horstmann, T. E.; Guerin, D. J.;
Miller, S. J. Angew. Chem. Int. Ed. 2000, 39, 3635; Angew.
Chem. 2000, 112, 3781.
The authors gratefully acknowledge the BMBF and Fonds der
Chemischen Industrie for generous financial support.
References
(7) General Procedure for the Michael Reaction: 2-Nitro-
propane (0.63 mmol) was added to a stirred solution of
2-cyclohexen-1-one (0.50 mmol), additive (0.50 mmol) and
peptide catalyst (15 mol%) in pre-dried solvent (DMF or
DMSO, 4 mL), and the reaction mixture was stirred at r.t. for
5 d. The solvent was evaporated and the residue was
dissolved in CHCl3 and washed with diluted aq HCl (3%).
The organic layer was dried with Na2SO4 and filtered, and
the solvents were evaporated. The residues were purified by
column chromatography on SiO2 (hexane–EtOAc) to afford
the desired product. The ee of the product was determined by
chiral HPLC analysis (Daicel Chiralpak AS) in comparison
with authentic racemic material: n-hexan–2-propanol =
80:20, flow rate 1 mL/min, l = 210 nm: tR1 = 28.44 min,
(1) (a) List, B.; Lerner, R. A.; Barbas, C. F. III J. Am. Chem. Soc.
2000, 122, 2395. (b) List, B. J. Am. Chem. Soc. 2000, 122,
9336. (c) Hanessian, S.; Pham, V. Org. Lett. 2000, 2, 2975.
(d) Sakthivel, K.; Notz, W.; Bui, T.; Barbas, C. F. III J. Am.
Chem. Soc. 2001, 123, 5260. (e) Enders, D.; Seki, A. Synlett
2002, 26. (f) List, B. J. Am. Chem. Soc. 2002, 124, 5656.
(g) Bahmanyar, S.; Houk, K. N.; Martin, H. J.; List, B. J. Am.
Chem. Soc. 2003, 125, 2475. (h) Gao, M. Z.; Gao, J.; Lane,
B. S.; Zingaro, R. A. Chem. Lett. 2003, 32, 524.
(i) Vignola, N.; List, B. J. Am. Chem. Soc. 2004, 126, 450.
(j) Bøgevig, A.; Sundén, H.; Córdova, A. Angew. Chem. Int.
Ed. 2004, 43, 1109; Angew. Chem. 2004, 116, 1129.
t
R2 = 30.31 min. 1H NMR (300 MHz, CDCl3): d = 2.48–2.34
(m, 3 H), 2.31–2.21 (m, 1 H), 2.19–2.08 (m, 2 H), 1.85–1.76
(m, 1 H), 1.71–1.53 (m, 1 H), 1.58 (s, 3 H), 1.57 (s, 3 H),
1.48–1.34 (m, 1 H) ppm. 13C NMR (150.8 MHz, CDCl3):
d = 208.9 (C=O), 90.6 (Cquat.), 46.5 (CH), 42.6 (CH2), 40.7
(CH2), 25.9 (CH2), 24.3 (CH2), 23.3 (CH3), 22.5 (CH3) ppm.
ESI-MS (positive ion): m/z = 208.1 [M + Na]+.
Synlett 2004, No. 14, 2624–2626 © Thieme Stuttgart · New York