Regio-controlled iodoaminocyclization reaction of an ambident nucleophile mediated by LiAl(Ot-Bu)4

Tetrahedron Letters

Volumn 38, Issue 4, 1997, Pages 615-618

  Kitagawa, Osamu ^a   Fujita, Masao ^a   Li, Hua ^a   Taguchi, Takeo ^a  

^a TOKYO UNIVERSITY OF PHARMACY AND LIFE SCIENCES   (Japan)

Author keywords

[No Author keywords available]

Indexed keywords

AMIDE; CARBAMIC ACID DERIVATIVE; REAGENT; UREA DERIVATIVE;

ARTICLE; CHEMICAL REACTION; CYCLIZATION; SYNTHESIS; TECHNIQUE;

EID: 0031013358     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0040-4039(96)02405-7     Document Type: Article

References (13)

1. (a) Corey, E. J.; Fleet, G. W. J.; Kato, M. Tetrahedron Lett. 1973, 3963-3966.
2. (b) Hirama, M.; Uei, M. Tetrahedron Lett. 1982, 23, 5307-5310.
3. For reviews of halocyclization: (c) Bartlett, P. A. "Asymmetric Synthesis", Ed. Morrison, J. D. Academic Press, Orland, 1984, Vol 3, Part B, p411.
4. (d) Gardillo, G.; Orena, M. Tetrahedron 1990, 46, 3321-3408.
5. (a) Biloski, A. J.; Wood, R. D.; Ganem B. J. Am. Chem. Soc. 1982, 104, 3233-3235.
6. (b) Hirama, M.; Iwashita, M.; Yamazaki, Y.; Ito, S. Tetrahedron Lett. 1984, 4963-4964.
7. Knapp, S.; Levorse, A. J. Org. Chem. 1988, 53, 4006-4014.
8. 3 gave a mixture of O-and N-cyclized products in a ratio of 2 : 1.
9. The preparation of 5-membered lactam through iodocyclization of unsaturated thioimidate was reported, (a) Kano, S.; Yokomatsu, T.; Iwasawa, H.; Shibuya, S. Heterocycles, 1987,26, 359-362.
10. (b) Takahata, H.; Takamatsu, T.; Mozumi, M.; Chen, Y-S.; Yamazaki, T.; Aoe, K. J. Chem. Soc., Chem. Commun. 1987, 1627-1629.
11. 3) δ: 4.9, 14.3, 48.3, 61.5, 76.1, 164.1, 166.7.
12. 4, and evaporated to dryness. Purification of the residue by column chromatography (hexane / AcOEt = 5) gave 2a (127 mg, 85 %).
13. Carbamates 1a, If, ureas 1b, 1g, and amides 1c, 1h could be easily prepared through the reaction of ethoxycarbonyl isocyanate with alchols, amines, and Grignard reagents, respectively.