Titanium catalysis in the Ugi reaction of α-amino acids with aromatic aldehydes

Organic Letters

Volumn 6, Issue 19, 2004, Pages 3281-3284

  Godet, Thomas ^a   Bonvin, Yannick ^a   Vincent, Guillaume ^a   Merle, Daphné ^b   Thozet, Alain ^b   Ciufolini, Marco A ^a  

^a UNIVERSITÉ LYON 1   (France)

^b UNIVERSITÉ LYON 1   (France)

Author keywords

[No Author keywords available]

Indexed keywords

ALDEHYDE; ALPHA AMINO ACID; ISONITRILE DERIVATIVE; TITANIUM DERIVATIVE;

ARTICLE; CATALYSIS; CATALYST; CHEMICAL REACTION; DIASTEREOISOMER; REACTION ANALYSIS;

ALDEHYDES; AMINO ACIDS; CATALYSIS; MOLECULAR STRUCTURE; NITROGEN COMPOUNDS; STEREOISOMERISM; TITANIUM;

EID: 4644278676     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol048850x     Document Type: Article

References (20)

1. Cf.: Roth, E.; Altman, J.; Kapon, M.; Ben-Ishai, D. Tetrahedron 1995, 51, 801.
2. E.g., Gosselin, F.; Roy, A.; O'Shea, P. D.; Chen, C.; Volante, R. P. Org. Lett. 2004, 6, 641.
3. Recent review: Dömling, A.; Ugi, I. Angew. Chem., Int. Ed. 2000, 39, 3168.
4. For instance: (a) Demharter, A.; Hörl, W.; Herdtweck, E.; Ugi, I. K. Angew. Chem., Int. Ed. Engl. 1996, 35, 173. (b) Ugi, I.; Hörl, W.; Hanusch-Kompa, C.; Schmid, T.; Herdtweck, E. Heterocycles 1998, 47, 955.
5. For instance: (a) Demharter, A.; Hörl, W.; Herdtweck, E.; Ugi, I. K. Angew. Chem., Int. Ed. Engl. 1996, 35, 173. (b) Ugi, I.; Hörl, W.; Hanusch-Kompa, C.; Schmid, T.; Herdtweck, E. Heterocycles 1998, 47, 955.
6. For instance: (a) Janvier, P.: Sun, X.; Bienaymé, H.; Zhu, Z. J. Am. Chem. Soc. 2001, 124, 2560. (b) Dyker, G.; Breitenstein, K.; Henkel, G. Tetrahedron: Asymmetry 2002, 13, 1929. Brief review: (e) Dyker, G. Angew. Chem., Int. Ed. Engl. 1997, 36, 1700.
7. For instance: (a) Janvier, P.: Sun, X.; Bienaymé, H.; Zhu, Z. J. Am. Chem. Soc. 2001, 124, 2560. (b) Dyker, G.; Breitenstein, K.; Henkel, G. Tetrahedron: Asymmetry 2002, 13, 1929. Brief review: (e) Dyker, G. Angew. Chem., Int. Ed. Engl. 1997, 36, 1700.
8. For instance: (a) Janvier, P.: Sun, X.; Bienaymé, H.; Zhu, Z. J. Am. Chem. Soc. 2001, 124, 2560. (b) Dyker, G.; Breitenstein, K.; Henkel, G. Tetrahedron: Asymmetry 2002, 13, 1929. Brief review: (e) Dyker, G. Angew. Chem., Int. Ed. Engl. 1997, 36, 1700.
9. Cf. Park, S. J.; Keum, G.; Kang, S. B.; Koh, H. Y.; Kim, Y. Tetrahedron Lett. 1998, 39, 7109.
10. Pirrung, M. C.; Das Sarma, K. J. Am. Chem. Soc. 2004, 126, 444.
11. Cf., e.g.: Saito, K.; Tago, T.; Masuyama, T.; Nishide, H. Angew. Chem., Int. Ed. 2004, 43, 730
12. Lewis acids have been used in certain multicomponent condensations involving isonitriles; cf.: Keung, W.; Bakir, F.; Patron, A. P.; Rogers, D.; Priest, C. D.; Darmohusodo V. Tetrahedron Lett. 2004, 45, 733.
13. 2 (72 h, 50%, dr = 9).
14. 4), filtered, and concentrated. The residue was purified by silica gel chromatography.
15. 4/MeOH procedure is applicable to reactions involving aliphatic aldehydes. While excellent yields of products are obtained, the substantial increase of the rate of such reactions results in significant erosion of diastereoselectivity relative to the original Ugi procedure, consistent with the reactivity-selectivity principle.
16. Prepared by addition of acetyl chloride to dry MeOH.
17. The same product was obtained upon refluxing a solution of 9e in HCOOH but in a diminished 30% yield.
18. The major isomer, a crystalline substance, was characterized by X-ray diffractometry.
19. The structure of this racemic product was confirmed by X-ray diffractometry.
20. Bronsted acids were also ineffective promoters.