Catalytic, asymmetric Mannich-type reactions of N-acylimino esters: Reactivity, diastereo- and enantioselectivity, and application to synthesis of N-acylated amino acid derivatives

Journal of the American Chemical Society

Volumn 125, Issue 9, 2003, Pages 2507-2515

  Kobayashi, Shu ^a   Matsubara, Ryosuke ^a   Nakamura, Yoshitaka ^a   Kitagawa, Hidetoshi ^a   Sugiura, Masaharu ^a  

^a UNIVERSITY OF TOKYO   (Japan)

Author keywords

[No Author keywords available]

Indexed keywords

ENANTIOSELECTIVITIES;

CATALYSIS; CATALYSTS; ETHERS; FOURIER TRANSFORM INFRARED SPECTROSCOPY; STEREOCHEMISTRY; SYNTHESIS (CHEMICAL); X RAY CRYSTALLOGRAPHY;

ESTERS;

AMIDE; AMINO ACID DERIVATIVE; CERAMIDE; COPPER DERIVATIVE; DIAMINE; ESTER; MANNICH BASE; N ACYLAMINO ACID; SILANE DERIVATIVE; SPHINGOMYELIN;

AMINO ACID SYNTHESIS; ARTICLE; ASYMMETRIC SYNTHESIS; CATALYSIS; CATALYST; CHEMICAL STRUCTURE; CHEMOREACTIVITY; CHIRALITY; DIASTEREOISOMER; ENANTIOMER; ENANTIOSELECTIVITY; INFRARED SPECTROSCOPY; MANNICH REACTION; QUANTUM YIELD; REACTION ANALYSIS; STEREOCHEMISTRY; X RAY CRYSTALLOGRAPHY;

ACYLATION; AMIDES; AMINO ACIDS; CATALYSIS; CRYSTALLOGRAPHY, X-RAY; MOLECULAR STRUCTURE; STEREOISOMERISM;

EID: 0037420331     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja0281840     Document Type: Article

References (87)

1. (a) Helms, G. L.; Moore, R. E.; Niemczura, W. P.; Patterson, G. M. L.; Tomer, K. B.; Gross, M. L. J. Org. Chem. 1988, 53, 1298.
2. (b) Matsunaga, S.; Fusetani, N.; Hashimoto, K.; Wälchli, M. J. Am. Chem. Soc. 1989, 111, 2582.
3. (c) Humphrey, J. M.; Chamberlin, A. R. Chem. Rev. 1997, 97, 2243.
4. (d) von Döhren, H.; Keller, U.; Vater, J.; Zocher, R. Chem. Rev. 1997, 97, 2675.
5. (e) Dickson, R. C. Annu. Rec. Biochem. 1998, 67, 27.
6. (f) Kolter, T.; Sandhoff, K. Angew. Chem. Int. Ed. Engl. 1999, 38, 1532.
7. (a) Weinreb, S. M.; Scola, P. A. Chem. Rev. 1989, 89, 1525. To our knowledge, α-imino ester was first used as a precursor to α-amino acid by Achmatowicz Jr. (b) Achmatowicz Jr., O.; Pietraszkiewicz, M. J. Chem. Soc., Chem. Commun. 1976, 484.
8. (a) Weinreb, S. M.; Scola, P. A. Chem. Rev. 1989, 89, 1525. To our knowledge, α-imino ester was first used as a precursor to α-amino acid by Achmatowicz Jr. (b) Achmatowicz Jr., O.; Pietraszkiewicz, M. J. Chem. Soc., Chem. Commun. 1976, 484.
9. (a) Fujii, A.; Hagiwara, E.; Sodeoka, M. J. Am. Chem. Soc. 1999, 121, 5450.
10. (b) Ferraris, D.; Dudding, T.; Young, B.; Drury, W. J., III; Lectka, T. J. Org. Chem. 1999, 64, 2168.
11. (c) Yamada, K.; Harwood, S. J.; Gröger, H.; Shibasaki, M. Angew. Chem., Int. Ed. Engl. 1999, 38, 3504.
12. (a) Kober, R.; Papadopoulos, K.; Miltz, W.; Enders, D.; Steglich, W. Reuter, H.; Puff, H. Tetrahedron 1985, 41, 1693.
13. (b) Münster, P.; Steglich, W. Synthesis 1987, 223.
14. (c) Bretschneider, T.; Miltz, W.; Münster, P.; Steglich, W. Tetrahedron 1988, 44, 5403.
15. (d) Saaby, S.; Fang, X.; Gathergood, N.; Jergensen, K. A. Angew. Chem., Int. Ed. 2000, 39, 4114.
16. (e) Dudding, T.; Hafez, A. M.; Taggi, A. E.; Wagerle, T. R.; Lectka, T. Org. Lett. 2002, 4, 387. For a review of N-acyliminium ions and related intermediates, see Speckamp, W. N.; Moolenaar, M. J. Tetrahedron 2000, 56, 3817.
17. (e) Dudding, T.; Hafez, A. M.; Taggi, A. E.; Wagerle, T. R.; Lectka, T. Org. Lett. 2002, 4, 387. For a review of N-acyliminium ions and related intermediates, see Speckamp, W. N.; Moolenaar, M. J. Tetrahedron 2000, 56, 3817.
18. Kobayashi, S.; Kitagawa, H.; Matsubara, R. J. Comb. Chem. 2001, 3, 401.
19. Kobayashi, S.; Matsubara, R.; Kitagawa, H. Org. Lett. 2002, 4, 143.
20. (a) Mimoun, H.; Laumer, J. Y. S.; Giannini, L.; Scopelliti, R.; Floriani, C. J. Am. Chem. Soc. 1999, 121, 6158.
21. (b) Cavallo, L.; Cucciolito, M. E.; Martino, A. D.; Giordano, F.; Orabona, I.; Vitagliano, A. Chem. Eur. J. 2000, 6, 1127.
22. (c) Kobayashi, S.; Hamada, T.; Manabe, K. J. Am. Chem. Soc. 2002, 124, 5640, and references therein.
23. 3CN, see: Kubas, G. J. Inorganic Synthesis; Shriver, D. F., Ed.; Plenum: New York, 1979; Vol. XIX, p 90.
24. Ferraris, D.; Young, B.; Cox, C.; Dudding, T.; Drury, W. J., III.; Ryzhkov, L.; Taggi, A. E.; Lectka, T. J. Am. Chem. Soc. 2002, 124, 67.
25. For the use of the Cu - BINAP system in enantioselective reactions of α-imino esters, see: (a) Ferraris, D.; Young, B.; Dudding, T.; Lectka, T. J. Am. Chem. Soc. 1998, 120, 4548. (b) Drury, W. J., III.; Ferraris, D.; Cox, C.; Young, B.; Lectka, T. J. Am. Chem. Soc. 1998, 120, 11 006. (c) Yao, S.; Johannsen, M.; Hazell, R. G.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 1998, 37, 3121. (d) Yao, S.; Fang, X.; Jørgensen, K. A. Chem. Commun. 1998, 2547. (e) Fang, X.; Johannsen. M.; Yao, S.; Gathergood, N.; Hazell, R. G.; Jørgensen, K. A. J. Org. Chem. 1999, 64, 4844. (f) Juhl, K.; Hazell, R. G.; Jørgensen, K. A. J. Chem. Soc., Perkin Trans. I 1999, 2293. (g) Johannsen, M. Chem. Commun. 1999, 2233. (h) Saaby, S.; Fang, X.; Gathergood, N.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 2000, 39, 4114. (i) Yao, S.; Saaby, S.; Hazell, R. G.; Jørgensen, K. A. Chem. Eur. J. 2000, 6, 2435. (j) Knudsen, K. R.; Risgaard, T.; Nishiwaki, N.; Gothelf, K. V.; Jørgensen, K. A. J. Am. Chem. Soc. 2001, 123, 5843. (k) Nishiwaki, N.; Knudsen, K. R.; Gothelf, K. V.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 2001, 40, 2992. Cf. (l) Krüger, J.; Carreira, E. M. J. Am. Chem. Soc. 1998, 120, 837.
26. For the use of the Cu - BINAP system in enantioselective reactions of α-imino esters, see: (a) Ferraris, D.; Young, B.; Dudding, T.; Lectka, T. J. Am. Chem. Soc. 1998, 120, 4548. (b) Drury, W. J., III.; Ferraris, D.; Cox, C.; Young, B.; Lectka, T. J. Am. Chem. Soc. 1998, 120, 11 006. (c) Yao, S.; Johannsen, M.; Hazell, R. G.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 1998, 37, 3121. (d) Yao, S.; Fang, X.; Jørgensen, K. A. Chem. Commun. 1998, 2547. (e) Fang, X.; Johannsen. M.; Yao, S.; Gathergood, N.; Hazell, R. G.; Jørgensen, K. A. J. Org. Chem. 1999, 64, 4844. (f) Juhl, K.; Hazell, R. G.; Jørgensen, K. A. J. Chem. Soc., Perkin Trans. I 1999, 2293. (g) Johannsen, M. Chem. Commun. 1999, 2233. (h) Saaby, S.; Fang, X.; Gathergood, N.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 2000, 39, 4114. (i) Yao, S.; Saaby, S.; Hazell, R. G.; Jørgensen, K. A. Chem. Eur. J. 2000, 6, 2435. (j) Knudsen, K. R.; Risgaard, T.; Nishiwaki, N.; Gothelf, K. V.; Jørgensen, K. A. J. Am. Chem. Soc. 2001, 123, 5843. (k) Nishiwaki, N.; Knudsen, K. R.; Gothelf, K. V.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 2001, 40, 2992. Cf. (l) Krüger, J.; Carreira, E. M. J. Am. Chem. Soc. 1998, 120, 837.
27. For the use of the Cu - BINAP system in enantioselective reactions of α-imino esters, see: (a) Ferraris, D.; Young, B.; Dudding, T.; Lectka, T. J. Am. Chem. Soc. 1998, 120, 4548. (b) Drury, W. J., III.; Ferraris, D.; Cox, C.; Young, B.; Lectka, T. J. Am. Chem. Soc. 1998, 120, 11 006. (c) Yao, S.; Johannsen, M.; Hazell, R. G.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 1998, 37, 3121. (d) Yao, S.; Fang, X.; Jørgensen, K. A. Chem. Commun. 1998, 2547. (e) Fang, X.; Johannsen. M.; Yao, S.; Gathergood, N.; Hazell, R. G.; Jørgensen, K. A. J. Org. Chem. 1999, 64, 4844. (f) Juhl, K.; Hazell, R. G.; Jørgensen, K. A. J. Chem. Soc., Perkin Trans. I 1999, 2293. (g) Johannsen, M. Chem. Commun. 1999, 2233. (h) Saaby, S.; Fang, X.; Gathergood, N.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 2000, 39, 4114. (i) Yao, S.; Saaby, S.; Hazell, R. G.; Jørgensen, K. A. Chem. Eur. J. 2000, 6, 2435. (j) Knudsen, K. R.; Risgaard, T.; Nishiwaki, N.; Gothelf, K. V.; Jørgensen, K. A. J. Am. Chem. Soc. 2001, 123, 5843. (k) Nishiwaki, N.; Knudsen, K. R.; Gothelf, K. V.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 2001, 40, 2992. Cf. (l) Krüger, J.; Carreira, E. M. J. Am. Chem. Soc. 1998, 120, 837.
28. For the use of the Cu - BINAP system in enantioselective reactions of α-imino esters, see: (a) Ferraris, D.; Young, B.; Dudding, T.; Lectka, T. J. Am. Chem. Soc. 1998, 120, 4548. (b) Drury, W. J., III.; Ferraris, D.; Cox, C.; Young, B.; Lectka, T. J. Am. Chem. Soc. 1998, 120, 11 006. (c) Yao, S.; Johannsen, M.; Hazell, R. G.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 1998, 37, 3121. (d) Yao, S.; Fang, X.; Jørgensen, K. A. Chem. Commun. 1998, 2547. (e) Fang, X.; Johannsen. M.; Yao, S.; Gathergood, N.; Hazell, R. G.; Jørgensen, K. A. J. Org. Chem. 1999, 64, 4844. (f) Juhl, K.; Hazell, R. G.; Jørgensen, K. A. J. Chem. Soc., Perkin Trans. I 1999, 2293. (g) Johannsen, M. Chem. Commun. 1999, 2233. (h) Saaby, S.; Fang, X.; Gathergood, N.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 2000, 39, 4114. (i) Yao, S.; Saaby, S.; Hazell, R. G.; Jørgensen, K. A. Chem. Eur. J. 2000, 6, 2435. (j) Knudsen, K. R.; Risgaard, T.; Nishiwaki, N.; Gothelf, K. V.; Jørgensen, K. A. J. Am. Chem. Soc. 2001, 123, 5843. (k) Nishiwaki, N.; Knudsen, K. R.; Gothelf, K. V.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 2001, 40, 2992. Cf. (l) Krüger, J.; Carreira, E. M. J. Am. Chem. Soc. 1998, 120, 837.
29. For the use of the Cu - BINAP system in enantioselective reactions of α-imino esters, see: (a) Ferraris, D.; Young, B.; Dudding, T.; Lectka, T. J. Am. Chem. Soc. 1998, 120, 4548. (b) Drury, W. J., III.; Ferraris, D.; Cox, C.; Young, B.; Lectka, T. J. Am. Chem. Soc. 1998, 120, 11 006. (c) Yao, S.; Johannsen, M.; Hazell, R. G.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 1998, 37, 3121. (d) Yao, S.; Fang, X.; Jørgensen, K. A. Chem. Commun. 1998, 2547. (e) Fang, X.; Johannsen. M.; Yao, S.; Gathergood, N.; Hazell, R. G.; Jørgensen, K. A. J. Org. Chem. 1999, 64, 4844. (f) Juhl, K.; Hazell, R. G.; Jørgensen, K. A. J. Chem. Soc., Perkin Trans. I 1999, 2293. (g) Johannsen, M. Chem. Commun. 1999, 2233. (h) Saaby, S.; Fang, X.; Gathergood, N.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 2000, 39, 4114. (i) Yao, S.; Saaby, S.; Hazell, R. G.; Jørgensen, K. A. Chem. Eur. J. 2000, 6, 2435. (j) Knudsen, K. R.; Risgaard, T.; Nishiwaki, N.; Gothelf, K. V.; Jørgensen, K. A. J. Am. Chem. Soc. 2001, 123, 5843. (k) Nishiwaki, N.; Knudsen, K. R.; Gothelf, K. V.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 2001, 40, 2992. Cf. (l) Krüger, J.; Carreira, E. M. J. Am. Chem. Soc. 1998, 120, 837.
30. For the use of the Cu - BINAP system in enantioselective reactions of α-imino esters, see: (a) Ferraris, D.; Young, B.; Dudding, T.; Lectka, T. J. Am. Chem. Soc. 1998, 120, 4548. (b) Drury, W. J., III.; Ferraris, D.; Cox, C.; Young, B.; Lectka, T. J. Am. Chem. Soc. 1998, 120, 11 006. (c) Yao, S.; Johannsen, M.; Hazell, R. G.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 1998, 37, 3121. (d) Yao, S.; Fang, X.; Jørgensen, K. A. Chem. Commun. 1998, 2547. (e) Fang, X.; Johannsen. M.; Yao, S.; Gathergood, N.; Hazell, R. G.; Jørgensen, K. A. J. Org. Chem. 1999, 64, 4844. (f) Juhl, K.; Hazell, R. G.; Jørgensen, K. A. J. Chem. Soc., Perkin Trans. I 1999, 2293. (g) Johannsen, M. Chem. Commun. 1999, 2233. (h) Saaby, S.; Fang, X.; Gathergood, N.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 2000, 39, 4114. (i) Yao, S.; Saaby, S.; Hazell, R. G.; Jørgensen, K. A. Chem. Eur. J. 2000, 6, 2435. (j) Knudsen, K. R.; Risgaard, T.; Nishiwaki, N.; Gothelf, K. V.; Jørgensen, K. A. J. Am. Chem. Soc. 2001, 123, 5843. (k) Nishiwaki, N.; Knudsen, K. R.; Gothelf, K. V.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 2001, 40, 2992. Cf. (l) Krüger, J.; Carreira, E. M. J. Am. Chem. Soc. 1998, 120, 837.
31. For the use of the Cu - BINAP system in enantioselective reactions of α-imino esters, see: (a) Ferraris, D.; Young, B.; Dudding, T.; Lectka, T. J. Am. Chem. Soc. 1998, 120, 4548. (b) Drury, W. J., III.; Ferraris, D.; Cox, C.; Young, B.; Lectka, T. J. Am. Chem. Soc. 1998, 120, 11 006. (c) Yao, S.; Johannsen, M.; Hazell, R. G.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 1998, 37, 3121. (d) Yao, S.; Fang, X.; Jørgensen, K. A. Chem. Commun. 1998, 2547. (e) Fang, X.; Johannsen. M.; Yao, S.; Gathergood, N.; Hazell, R. G.; Jørgensen, K. A. J. Org. Chem. 1999, 64, 4844. (f) Juhl, K.; Hazell, R. G.; Jørgensen, K. A. J. Chem. Soc., Perkin Trans. I 1999, 2293. (g) Johannsen, M. Chem. Commun. 1999, 2233. (h) Saaby, S.; Fang, X.; Gathergood, N.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 2000, 39, 4114. (i) Yao, S.; Saaby, S.; Hazell, R. G.; Jørgensen, K. A. Chem. Eur. J. 2000, 6, 2435. (j) Knudsen, K. R.; Risgaard, T.; Nishiwaki, N.; Gothelf, K. V.; Jørgensen, K. A. J. Am. Chem. Soc. 2001, 123, 5843. (k) Nishiwaki, N.; Knudsen, K. R.; Gothelf, K. V.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 2001, 40, 2992. Cf. (l) Krüger, J.; Carreira, E. M. J. Am. Chem. Soc. 1998, 120, 837.
32. For the use of the Cu - BINAP system in enantioselective reactions of α-imino esters, see: (a) Ferraris, D.; Young, B.; Dudding, T.; Lectka, T. J. Am. Chem. Soc. 1998, 120, 4548. (b) Drury, W. J., III.; Ferraris, D.; Cox, C.; Young, B.; Lectka, T. J. Am. Chem. Soc. 1998, 120, 11 006. (c) Yao, S.; Johannsen, M.; Hazell, R. G.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 1998, 37, 3121. (d) Yao, S.; Fang, X.; Jørgensen, K. A. Chem. Commun. 1998, 2547. (e) Fang, X.; Johannsen. M.; Yao, S.; Gathergood, N.; Hazell, R. G.; Jørgensen, K. A. J. Org. Chem. 1999, 64, 4844. (f) Juhl, K.; Hazell, R. G.; Jørgensen, K. A. J. Chem. Soc., Perkin Trans. I 1999, 2293. (g) Johannsen, M. Chem. Commun. 1999, 2233. (h) Saaby, S.; Fang, X.; Gathergood, N.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 2000, 39, 4114. (i) Yao, S.; Saaby, S.; Hazell, R. G.; Jørgensen, K. A. Chem. Eur. J. 2000, 6, 2435. (j) Knudsen, K. R.; Risgaard, T.; Nishiwaki, N.; Gothelf, K. V.; Jørgensen, K. A. J. Am. Chem. Soc. 2001, 123, 5843. (k) Nishiwaki, N.; Knudsen, K. R.; Gothelf, K. V.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 2001, 40, 2992. Cf. (l) Krüger, J.; Carreira, E. M. J. Am. Chem. Soc. 1998, 120, 837.
33. For the use of the Cu - BINAP system in enantioselective reactions of α-imino esters, see: (a) Ferraris, D.; Young, B.; Dudding, T.; Lectka, T. J. Am. Chem. Soc. 1998, 120, 4548. (b) Drury, W. J., III.; Ferraris, D.; Cox, C.; Young, B.; Lectka, T. J. Am. Chem. Soc. 1998, 120, 11 006. (c) Yao, S.; Johannsen, M.; Hazell, R. G.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 1998, 37, 3121. (d) Yao, S.; Fang, X.; Jørgensen, K. A. Chem. Commun. 1998, 2547. (e) Fang, X.; Johannsen. M.; Yao, S.; Gathergood, N.; Hazell, R. G.; Jørgensen, K. A. J. Org. Chem. 1999, 64, 4844. (f) Juhl, K.; Hazell, R. G.; Jørgensen, K. A. J. Chem. Soc., Perkin Trans. I 1999, 2293. (g) Johannsen, M. Chem. Commun. 1999, 2233. (h) Saaby, S.; Fang, X.; Gathergood, N.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 2000, 39, 4114. (i) Yao, S.; Saaby, S.; Hazell, R. G.; Jørgensen, K. A. Chem. Eur. J. 2000, 6, 2435. (j) Knudsen, K. R.; Risgaard, T.; Nishiwaki, N.; Gothelf, K. V.; Jørgensen, K. A. J. Am. Chem. Soc. 2001, 123, 5843. (k) Nishiwaki, N.; Knudsen, K. R.; Gothelf, K. V.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 2001, 40, 2992. Cf. (l) Krüger, J.; Carreira, E. M. J. Am. Chem. Soc. 1998, 120, 837.
34. For the use of the Cu - BINAP system in enantioselective reactions of α-imino esters, see: (a) Ferraris, D.; Young, B.; Dudding, T.; Lectka, T. J. Am. Chem. Soc. 1998, 120, 4548. (b) Drury, W. J., III.; Ferraris, D.; Cox, C.; Young, B.; Lectka, T. J. Am. Chem. Soc. 1998, 120, 11 006. (c) Yao, S.; Johannsen, M.; Hazell, R. G.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 1998, 37, 3121. (d) Yao, S.; Fang, X.; Jørgensen, K. A. Chem. Commun. 1998, 2547. (e) Fang, X.; Johannsen. M.; Yao, S.; Gathergood, N.; Hazell, R. G.; Jørgensen, K. A. J. Org. Chem. 1999, 64, 4844. (f) Juhl, K.; Hazell, R. G.; Jørgensen, K. A. J. Chem. Soc., Perkin Trans. I 1999, 2293. (g) Johannsen, M. Chem. Commun. 1999, 2233. (h) Saaby, S.; Fang, X.; Gathergood, N.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 2000, 39, 4114. (i) Yao, S.; Saaby, S.; Hazell, R. G.; Jørgensen, K. A. Chem. Eur. J. 2000, 6, 2435. (j) Knudsen, K. R.; Risgaard, T.; Nishiwaki, N.; Gothelf, K. V.; Jørgensen, K. A. J. Am. Chem. Soc. 2001, 123, 5843. (k) Nishiwaki, N.; Knudsen, K. R.; Gothelf, K. V.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 2001, 40, 2992. Cf. (l) Krüger, J.; Carreira, E. M. J. Am. Chem. Soc. 1998, 120, 837.
35. For the use of the Cu - BINAP system in enantioselective reactions of α-imino esters, see: (a) Ferraris, D.; Young, B.; Dudding, T.; Lectka, T. J. Am. Chem. Soc. 1998, 120, 4548. (b) Drury, W. J., III.; Ferraris, D.; Cox, C.; Young, B.; Lectka, T. J. Am. Chem. Soc. 1998, 120, 11 006. (c) Yao, S.; Johannsen, M.; Hazell, R. G.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 1998, 37, 3121. (d) Yao, S.; Fang, X.; Jørgensen, K. A. Chem. Commun. 1998, 2547. (e) Fang, X.; Johannsen. M.; Yao, S.; Gathergood, N.; Hazell, R. G.; Jørgensen, K. A. J. Org. Chem. 1999, 64, 4844. (f) Juhl, K.; Hazell, R. G.; Jørgensen, K. A. J. Chem. Soc., Perkin Trans. I 1999, 2293. (g) Johannsen, M. Chem. Commun. 1999, 2233. (h) Saaby, S.; Fang, X.; Gathergood, N.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 2000, 39, 4114. (i) Yao, S.; Saaby, S.; Hazell, R. G.; Jørgensen, K. A. Chem. Eur. J. 2000, 6, 2435. (j) Knudsen, K. R.; Risgaard, T.; Nishiwaki, N.; Gothelf, K. V.; Jørgensen, K. A. J. Am. Chem. Soc. 2001, 123, 5843. (k) Nishiwaki, N.; Knudsen, K. R.; Gothelf, K. V.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 2001, 40, 2992. Cf. (l) Krüger, J.; Carreira, E. M. J. Am. Chem. Soc. 1998, 120, 837.
36. For the use of the Cu - BINAP system in enantioselective reactions of α-imino esters, see: (a) Ferraris, D.; Young, B.; Dudding, T.; Lectka, T. J. Am. Chem. Soc. 1998, 120, 4548. (b) Drury, W. J., III.; Ferraris, D.; Cox, C.; Young, B.; Lectka, T. J. Am. Chem. Soc. 1998, 120, 11 006. (c) Yao, S.; Johannsen, M.; Hazell, R. G.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 1998, 37, 3121. (d) Yao, S.; Fang, X.; Jørgensen, K. A. Chem. Commun. 1998, 2547. (e) Fang, X.; Johannsen. M.; Yao, S.; Gathergood, N.; Hazell, R. G.; Jørgensen, K. A. J. Org. Chem. 1999, 64, 4844. (f) Juhl, K.; Hazell, R. G.; Jørgensen, K. A. J. Chem. Soc., Perkin Trans. I 1999, 2293. (g) Johannsen, M. Chem. Commun. 1999, 2233. (h) Saaby, S.; Fang, X.; Gathergood, N.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 2000, 39, 4114. (i) Yao, S.; Saaby, S.; Hazell, R. G.; Jørgensen, K. A. Chem. Eur. J. 2000, 6, 2435. (j) Knudsen, K. R.; Risgaard, T.; Nishiwaki, N.; Gothelf, K. V.; Jørgensen, K. A. J. Am. Chem. Soc. 2001, 123, 5843. (k) Nishiwaki, N.; Knudsen, K. R.; Gothelf, K. V.; Jørgensen, K. A. Angew. Chem., Int. Ed. Engl. 2001, 40, 2992. Cf. (l) Krüger, J.; Carreira, E. M. J. Am. Chem. Soc. 1998, 120, 837.
37. For other chiral Cu-catalyzed reactions, see, for example: (a) Wei, C.; Li, C. J. J. Am. Chem. Soc. 2002, 124, 5638. (b) Evans, D. A.; Tregay, S. W.; Burgey, C. S.; Paras, N. A.; Vojkovsky, T. J. Am. Chem. Soc. 2000, 122, 7936-7943. (c) Johnson, J. S.; Evans, D. A. Acc. Chem. Res. 2000, 33, 325. (d) Bromidge, S.; Wilson, P. C.; Whiting, A. Tetrahedron Lett. 1998, 39, 8905. (e) Jnoff, E.; Ghosez, L. J. Am. Chem. Soc. 1999, 121, 2617. (f) Audrain, H.; Jørgensen, K. A. J. Am. Chem. Soc. 2000, 122, 11 543. (g) Gathergood, N.; Zhuang, W.; Jørgensen, K. A. J. Am. Chem. Soc. 2000, 122, 12 517.
38. For other chiral Cu-catalyzed reactions, see, for example: (a) Wei, C.; Li, C. J. J. Am. Chem. Soc. 2002, 124, 5638. (b) Evans, D. A.; Tregay, S. W.; Burgey, C. S.; Paras, N. A.; Vojkovsky, T. J. Am. Chem. Soc. 2000, 122, 7936-7943. (c) Johnson, J. S.; Evans, D. A. Acc. Chem. Res. 2000, 33, 325. (d) Bromidge, S.; Wilson, P. C.; Whiting, A. Tetrahedron Lett. 1998, 39, 8905. (e) Jnoff, E.; Ghosez, L. J. Am. Chem. Soc. 1999, 121, 2617. (f) Audrain, H.; Jørgensen, K. A. J. Am. Chem. Soc. 2000, 122, 11 543. (g) Gathergood, N.; Zhuang, W.; Jørgensen, K. A. J. Am. Chem. Soc. 2000, 122, 12 517.
39. For other chiral Cu-catalyzed reactions, see, for example: (a) Wei, C.; Li, C. J. J. Am. Chem. Soc. 2002, 124, 5638. (b) Evans, D. A.; Tregay, S. W.; Burgey, C. S.; Paras, N. A.; Vojkovsky, T. J. Am. Chem. Soc. 2000, 122, 7936-7943. (c) Johnson, J. S.; Evans, D. A. Acc. Chem. Res. 2000, 33, 325. (d) Bromidge, S.; Wilson, P. C.; Whiting, A. Tetrahedron Lett. 1998, 39, 8905. (e) Jnoff, E.; Ghosez, L. J. Am. Chem. Soc. 1999, 121, 2617. (f) Audrain, H.; Jørgensen, K. A. J. Am. Chem. Soc. 2000, 122, 11 543. (g) Gathergood, N.; Zhuang, W.; Jørgensen, K. A. J. Am. Chem. Soc. 2000, 122, 12 517.
40. For other chiral Cu-catalyzed reactions, see, for example: (a) Wei, C.; Li, C. J. J. Am. Chem. Soc. 2002, 124, 5638. (b) Evans, D. A.; Tregay, S. W.; Burgey, C. S.; Paras, N. A.; Vojkovsky, T. J. Am. Chem. Soc. 2000, 122, 7936-7943. (c) Johnson, J. S.; Evans, D. A. Acc. Chem. Res. 2000, 33, 325. (d) Bromidge, S.; Wilson, P. C.; Whiting, A. Tetrahedron Lett. 1998, 39, 8905. (e) Jnoff, E.; Ghosez, L. J. Am. Chem. Soc. 1999, 121, 2617. (f) Audrain, H.; Jørgensen, K. A. J. Am. Chem. Soc. 2000, 122, 11 543. (g) Gathergood, N.; Zhuang, W.; Jørgensen, K. A. J. Am. Chem. Soc. 2000, 122, 12 517.
41. For other chiral Cu-catalyzed reactions, see, for example: (a) Wei, C.; Li, C. J. J. Am. Chem. Soc. 2002, 124, 5638. (b) Evans, D. A.; Tregay, S. W.; Burgey, C. S.; Paras, N. A.; Vojkovsky, T. J. Am. Chem. Soc. 2000, 122, 7936-7943. (c) Johnson, J. S.; Evans, D. A. Acc. Chem. Res. 2000, 33, 325. (d) Bromidge, S.; Wilson, P. C.; Whiting, A. Tetrahedron Lett. 1998, 39, 8905. (e) Jnoff, E.; Ghosez, L. J. Am. Chem. Soc. 1999, 121, 2617. (f) Audrain, H.; Jørgensen, K. A. J. Am. Chem. Soc. 2000, 122, 11 543. (g) Gathergood, N.; Zhuang, W.; Jørgensen, K. A. J. Am. Chem. Soc. 2000, 122, 12 517.
42. For other chiral Cu-catalyzed reactions, see, for example: (a) Wei, C.; Li, C. J. J. Am. Chem. Soc. 2002, 124, 5638. (b) Evans, D. A.; Tregay, S. W.; Burgey, C. S.; Paras, N. A.; Vojkovsky, T. J. Am. Chem. Soc. 2000, 122, 7936-7943. (c) Johnson, J. S.; Evans, D. A. Acc. Chem. Res. 2000, 33, 325. (d) Bromidge, S.; Wilson, P. C.; Whiting, A. Tetrahedron Lett. 1998, 39, 8905. (e) Jnoff, E.; Ghosez, L. J. Am. Chem. Soc. 1999, 121, 2617. (f) Audrain, H.; Jørgensen, K. A. J. Am. Chem. Soc. 2000, 122, 11 543. (g) Gathergood, N.; Zhuang, W.; Jørgensen, K. A. J. Am. Chem. Soc. 2000, 122, 12 517.
43. For other chiral Cu-catalyzed reactions, see, for example: (a) Wei, C.; Li, C. J. J. Am. Chem. Soc. 2002, 124, 5638. (b) Evans, D. A.; Tregay, S. W.; Burgey, C. S.; Paras, N. A.; Vojkovsky, T. J. Am. Chem. Soc. 2000, 122, 7936-7943. (c) Johnson, J. S.; Evans, D. A. Acc. Chem. Res. 2000, 33, 325. (d) Bromidge, S.; Wilson, P. C.; Whiting, A. Tetrahedron Lett. 1998, 39, 8905. (e) Jnoff, E.; Ghosez, L. J. Am. Chem. Soc. 1999, 121, 2617. (f) Audrain, H.; Jørgensen, K. A. J. Am. Chem. Soc. 2000, 122, 11 543. (g) Gathergood, N.; Zhuang, W.; Jørgensen, K. A. J. Am. Chem. Soc. 2000, 122, 12 517.
44. 2-diamine complex was prepared according to the reported method. Evans, D. A.; Scheidt, K. A.; Johnston, J. N. Wills, M. C. J. Am. Chem. Soc. 2001, 123, 4480.
45. For examples using aspartic acid derivatives as chiral synthons, see: (a) Yoshida, T.; Takeshita, M.; Orita, H.; Kado, N.; Yasuda, S.; Kato, H.; Itoh, Y. Chem. Pharm. Bull. 1996, 44, 1128. (b) Humphrey, J. M.; Bridges R. J.; Hart, J. A.; Chamberlin, A. R. J. Org. Chem. 1994, 59, 2467. (c) Dunn, P. J.; Häner, R.; Rapoport, H. J. Org. Chem. 1990, 55, 5017. (d) McGarvey, G. J.; Williams, J. M.; Hiner, R. N.; Matsubara, Y.; Oh, T. J. Am. Chem. Soc. 1986, 108, 4943.
46. For examples using aspartic acid derivatives as chiral synthons, see: (a) Yoshida, T.; Takeshita, M.; Orita, H.; Kado, N.; Yasuda, S.; Kato, H.; Itoh, Y. Chem. Pharm. Bull. 1996, 44, 1128. (b) Humphrey, J. M.; Bridges R. J.; Hart, J. A.; Chamberlin, A. R. J. Org. Chem. 1994, 59, 2467. (c) Dunn, P. J.; Häner, R.; Rapoport, H. J. Org. Chem. 1990, 55, 5017. (d) McGarvey, G. J.; Williams, J. M.; Hiner, R. N.; Matsubara, Y.; Oh, T. J. Am. Chem. Soc. 1986, 108, 4943.
47. For examples using aspartic acid derivatives as chiral synthons, see: (a) Yoshida, T.; Takeshita, M.; Orita, H.; Kado, N.; Yasuda, S.; Kato, H.; Itoh, Y. Chem. Pharm. Bull. 1996, 44, 1128. (b) Humphrey, J. M.; Bridges R. J.; Hart, J. A.; Chamberlin, A. R. J. Org. Chem. 1994, 59, 2467. (c) Dunn, P. J.; Häner, R.; Rapoport, H. J. Org. Chem. 1990, 55, 5017. (d) McGarvey, G. J.; Williams, J. M.; Hiner, R. N.; Matsubara, Y.; Oh, T. J. Am. Chem. Soc. 1986, 108, 4943.
48. For examples using aspartic acid derivatives as chiral synthons, see: (a) Yoshida, T.; Takeshita, M.; Orita, H.; Kado, N.; Yasuda, S.; Kato, H.; Itoh, Y. Chem. Pharm. Bull. 1996, 44, 1128. (b) Humphrey, J. M.; Bridges R. J.; Hart, J. A.; Chamberlin, A. R. J. Org. Chem. 1994, 59, 2467. (c) Dunn, P. J.; Häner, R.; Rapoport, H. J. Org. Chem. 1990, 55, 5017. (d) McGarvey, G. J.; Williams, J. M.; Hiner, R. N.; Matsubara, Y.; Oh, T. J. Am. Chem. Soc. 1986, 108, 4943.
49. The asymmetric Mannich-type reaction with ester-derived ketene acetals using a Cu-BINAP catalyst was already reported by Lectka et al; however, the enantioselectivity for simple ester-derived ketene silyl acetals was moderate (∼72% ee) except for the coumarinone derived ketene silyl acetals. See ref 9.
50. Provided from Takasago Chemical Co. Ltd. For the preparation of xylyl-BINAP, see: Mashima, K.; Kusano, K.; Sato, N.; Matsumura, Y.; Nozaki, K.; Kumobayashi, H.; Sayo, N.; Hori, Y.; Ishizaki, T.; Akutagawa, S.; Takaya, H. J. Org. Chem. 1994, 59, 3064. The use of xylyl-BINAP, see, e.g.: Ohkuma, T.; Koizumi, M.; Doucet, H.; Pham, T.; Kozawa, M.; Murata, K.; Katayama, E.; Yokozawa, T.; Ikariya, T.; Noyori, R. J. Am. Chem. Soc. 1998, 120, 13 529.
51. Provided from Takasago Chemical Co. Ltd. For the preparation of xylyl-BINAP, see: Mashima, K.; Kusano, K.; Sato, N.; Matsumura, Y.; Nozaki, K.; Kumobayashi, H.; Sayo, N.; Hori, Y.; Ishizaki, T.; Akutagawa, S.; Takaya, H. J. Org. Chem. 1994, 59, 3064. The use of xylyl-BINAP, see, e.g.: Ohkuma, T.; Koizumi, M.; Doucet, H.; Pham, T.; Kozawa, M.; Murata, K.; Katayama, E.; Yokozawa, T.; Ikariya, T.; Noyori, R. J. Am. Chem. Soc. 1998, 120, 13 529.
52. 1H NMR spectrum data for the diastereomeric mixture of 13: Hirabayashi, S.; Ike, K.; Zanka, A.; Kawakami, T., Ichihara, M. World Intellectual Property Organization Patent 1992, WO9220652.
53. Ueno, M.; Kitagawa, H.; Ishitani, H.; Yasuda, S.; Nishijima, K.; Hanada, K.; Kobayashi, S. Tetrahedron Lett. 2001, 42, 7863.
54. Experimental details were shown in the Supporting Information.
55. The NMR spectra of 14 was compared with one of known compound 15. Details were shown in Supprting Information. (a) Barluenga, J.; Viado, A. L.; Aguilar, E.; Fustero, S.; Olano, B. J. Org. Chem. 1993, 58, 5972. (b) Gair, S.; Jackson, R. F. W.; Brown, P. A. Tetrahedron Lett. 1997, 38, 3059.
56. The NMR spectra of 14 was compared with one of known compound 15. Details were shown in Supprting Information. (a) Barluenga, J.; Viado, A. L.; Aguilar, E.; Fustero, S.; Olano, B. J. Org. Chem. 1993, 58, 5972. (b) Gair, S.; Jackson, R. F. W.; Brown, P. A. Tetrahedron Lett. 1997, 38, 3059.
57. (a) Kobayashi, S.; Ueno, M.; Ishitani, H. J. Am. Chem. Soc. 1998, 120, 431.
58. (b) Mukaiyama, T.; Shiina, I.; Uchiro, H.; Kobayashi, S. Bull. Chem. Soc. Jpn. 1994, 67, 1708.
59. (a) Merrill, A. H., Jr.; Sweeley, C. C. In Biochemistry of Lipids, Lipoproteins, and Membranes; Vance, D. E., Vance, J., Eds; Elsevier Science B. V.: Amsterdam, 1996; pp 309-339.
60. (b) Hannun, Y. A. Science 1996, 274, 1855.
61. (c) Hanada, K.; Nishijima, M.; Kiso, M.; Hasegawa, A.; Fujita, S.; Ogawa, T.; Akamatsu, Y. J. Biol. Chem. 1992, 267, 23 527.
62. (d) Kobayashi, S.; Furuta, T.; Hayashi, T.; Nishijima, M.; Hanada, K. J. Am. Chem. Soc. 1998, 120, 908.
63. Imashiro, R.; Sakurai, O.; Yamashita, T.; Horikawa, H. Tetrahedron 1998, 54, 10 657.
64. For catalytic enantioselective aldol reactions using alkyl vinyl ethers, see Carreira, E. M.; Lee, W.; Singer, R. A. J. Am. Chem. Soc. 1995, 117, 3649.
65. Experimental details were shown in Supporting Information.
66. Similar reaction pathways were reported. (a) Gizecki, P.; Dhal, R.; Toupet, L.; Dujardin, G. Org. Lett. 2000, 2, 585, and ref 2a. See also, (b) Kitajima, H.; Katsuki, T. Synlett 1997, 568. See also, ref 12.
67. Similar reaction pathways were reported. (a) Gizecki, P.; Dhal, R.; Toupet, L.; Dujardin, G. Org. Lett. 2000, 2, 585, and ref 2a. See also, (b) Kitajima, H.; Katsuki, T. Synlett 1997, 568. See also, ref 12.
68. 2O and diamine 3d was grown in a THF-hexane solvent system.
69. Two water molecules are abbreviated for clarification.
70. The copper center in a little distorted square planar geometry was also reported by Evans et al.: See ref 12.
71. Stewart, J. J. P. J. Comput. Chem. 1989, 10, 209-221.
72. Although the reliability of PM3 calculations for transition metal complexes with partially filled d-orbitals is controversial, there are several examples of PM3 calculations of Cu(II)-complexes. For examples, Evans et al. used PM3 calculations for Cu(II)-bisoxazoline complexes, and optimized structures were reported to be almost consistent with X-ray structures. They also reasonably explained enantioselectivity in several catalytic asymmetric reactions: Johnson, J. S.; Evans, D. A. Acc. Chem. Res. 2000, 33, 325, and references therein.
73. Although Cu(II) complexes usually adopt a square planar geometry rather than a tetrahedral geometry, several examples of tetrahedral Cu(II) complexes have been reported. For recent examples, see: (a) Beheshti, A.; Clegg, W.; Hyvadi, R.; Hekmat, H. F. Polyhedron 2002, 21, 1547. Jørgensen et al. also proposed tetrahedral transition state models to explain enantioselectivity in asymmetric hetero Diels - Alder Reactions and ene reactions catalyzed by chiral Cu(II) complexes. (b) Johannsen, M.; Jørgensen, K. A. J. Org. Chem. 1995, 60, 5757. (c) Johannsen, M.; Yao, S.; Graven, A.; Jørgensen, K. A. Pure Appl. Chem. 1998, 70, 1117.
74. Although Cu(II) complexes usually adopt a square planar geometry rather than a tetrahedral geometry, several examples of tetrahedral Cu(II) complexes have been reported. For recent examples, see: (a) Beheshti, A.; Clegg, W.; Hyvadi, R.; Hekmat, H. F. Polyhedron 2002, 21, 1547. Jørgensen et al. also proposed tetrahedral transition state models to explain enantioselectivity in asymmetric hetero Diels - Alder Reactions and ene reactions catalyzed by chiral Cu(II) complexes. (b) Johannsen, M.; Jørgensen, K. A. J. Org. Chem. 1995, 60, 5757. (c) Johannsen, M.; Yao, S.; Graven, A.; Jørgensen, K. A. Pure Appl. Chem. 1998, 70, 1117.
75. Although Cu(II) complexes usually adopt a square planar geometry rather than a tetrahedral geometry, several examples of tetrahedral Cu(II) complexes have been reported. For recent examples, see: (a) Beheshti, A.; Clegg, W.; Hyvadi, R.; Hekmat, H. F. Polyhedron 2002, 21, 1547. Jørgensen et al. also proposed tetrahedral transition state models to explain enantioselectivity in asymmetric hetero Diels - Alder Reactions and ene reactions catalyzed by chiral Cu(II) complexes. (b) Johannsen, M.; Jørgensen, K. A. J. Org. Chem. 1995, 60, 5757. (c) Johannsen, M.; Yao, S.; Graven, A.; Jørgensen, K. A. Pure Appl. Chem. 1998, 70, 1117.
76. Diastereoselections in additions of π-based nucleophiles (silyl enol ethers, allylic metals, etc.) to aldehydes or ketones have been discussed very well using open or cyclic transition state models. For aldol reactions, see: (a) Mahrwald, R. Chem. Rev. 1999, 99, 1095, and references therein. For allylations, see: (b) Yamamoto, Y.; Asao, N. Chem. Rev. 1993, 93, 2207, and references therein. For effects of olefin geometry of nucleophiles on the diastereoselection, see: (c) Keck, G. E.; Savin, K. A.; Cressman, E. N. K.; Abbott, D. E. J. Org. Chem. 1994, 59, 7889. (d) Roush, W. R.; Ando, K.; Powers, D. B.; Palkowitz, A. D.; Halterman, R. L. J. Am. Chem. Soc. 1990, 112, 6339.
77. Diastereoselections in additions of π-based nucleophiles (silyl enol ethers, allylic metals, etc.) to aldehydes or ketones have been discussed very well using open or cyclic transition state models. For aldol reactions, see: (a) Mahrwald, R. Chem. Rev. 1999, 99, 1095, and references therein. For allylations, see: (b) Yamamoto, Y.; Asao, N. Chem. Rev. 1993, 93, 2207, and references therein. For effects of olefin geometry of nucleophiles on the diastereoselection, see: (c) Keck, G. E.; Savin, K. A.; Cressman, E. N. K.; Abbott, D. E. J. Org. Chem. 1994, 59, 7889. (d) Roush, W. R.; Ando, K.; Powers, D. B.; Palkowitz, A. D.; Halterman, R. L. J. Am. Chem. Soc. 1990, 112, 6339.
78. Diastereoselections in additions of π-based nucleophiles (silyl enol ethers, allylic metals, etc.) to aldehydes or ketones have been discussed very well using open or cyclic transition state models. For aldol reactions, see: (a) Mahrwald, R. Chem. Rev. 1999, 99, 1095, and references therein. For allylations, see: (b) Yamamoto, Y.; Asao, N. Chem. Rev. 1993, 93, 2207, and references therein. For effects of olefin geometry of nucleophiles on the diastereoselection, see: (c) Keck, G. E.; Savin, K. A.; Cressman, E. N. K.; Abbott, D. E. J. Org. Chem. 1994, 59, 7889. (d) Roush, W. R.; Ando, K.; Powers, D. B.; Palkowitz, A. D.; Halterman, R. L. J. Am. Chem. Soc. 1990, 112, 6339.
79. Diastereoselections in additions of π-based nucleophiles (silyl enol ethers, allylic metals, etc.) to aldehydes or ketones have been discussed very well using open or cyclic transition state models. For aldol reactions, see: (a) Mahrwald, R. Chem. Rev. 1999, 99, 1095, and references therein. For allylations, see: (b) Yamamoto, Y.; Asao, N. Chem. Rev. 1993, 93, 2207, and references therein. For effects of olefin geometry of nucleophiles on the diastereoselection, see: (c) Keck, G. E.; Savin, K. A.; Cressman, E. N. K.; Abbott, D. E. J. Org. Chem. 1994, 59, 7889. (d) Roush, W. R.; Ando, K.; Powers, D. B.; Palkowitz, A. D.; Halterman, R. L. J. Am. Chem. Soc. 1990, 112, 6339.
80. Yasuda, S.; Kitagawa, H.; Ueno, M.; Ishitani, H.; Fukasawa, M.; Nishijima, M.; Kobayashi, S.; Hanada, K. J. Biol. Chem. 2001, 276, 43 994.
81. (a) Ueno, M.; Kitagawa, M.; Ishitani, H.; Yasuda, S.; Hanada, K.; Kobayashi, S. Tetrahedron Lett. 2001, 42, 7863.
82. (b) Ishitani, H.; Ueno, M.; Kobayashi, S. J. Am. Chem. Soc. 1997, 119, 7153.
83. (c) Ishitani, H.; Ueno, M.; Kobayashi, S. J. Am. Chem. Soc. 2000, 122, 8180.
84. (d) Kobayashi, S.; Ishitani, H.; Yamashita, Y.; Ueno, M.; Shimizu, H. Tetrahedron 2001, 57, 861. See also, 20
85. Pilli, R. A.; Russowsky, D.; Dias, L. C. J. Chem. Soc., Perkin Trans. I 1990, 1213. Syn-selective reduction of N-acyl-β-amino ketones has been reported recently. Keck, G. E.; Truong, A. P. Org. Lett. 2002, 4, 3131.
86. Pilli, R. A.; Russowsky, D.; Dias, L. C. J. Chem. Soc., Perkin Trans. I 1990, 1213. Syn-selective reduction of N-acyl-β-amino ketones has been reported recently. Keck, G. E.; Truong, A. P. Org. Lett. 2002, 4, 3131.
87. Direct recrystallization gave diastereo- and enantiomerically pure HPA-12. See Supporting Information.