Aprotic chloride and bromide-promoted alkyne-iminium ion cyclizations

Heterocycles

Volumn 42, Issue 2, 1996, Pages 549-552

  Murata, Yoshinori ^a,b   Overman, Larry E ^a  

^a UNIVERSITY OF CALIFORNIA   (United States)

^b PFIZER INC   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0142193737     PISSN: 03855414     EISSN: None     Source Type: Journal    
DOI: 10.3987/com-95-s96     Document Type: Article

References (17)

1. L. E. Overman and M. J. Sharp, J. Am. Chem. Soc., 1988, 110, 612 and 5934. L. E. Overman and A. K. Sarkar, Tetrahedron Lett., 1992, 33, 4103. H. Arnold, L. E. Overman, M. J. Sharp, and M. C. Witschel, Org. Synth., 1991, 70, 111.
2. L. E. Overman and M. J. Sharp, J. Am. Chem. Soc., 1988, 110, 612 and 5934. L. E. Overman and A. K. Sarkar, Tetrahedron Lett., 1992, 33, 4103. H. Arnold, L. E. Overman, M. J. Sharp, and M. C. Witschel, Org. Synth., 1991, 70, 111.
3. L. E. Overman and M. J. Sharp, J. Am. Chem. Soc., 1988, 110, 612 and 5934. L. E. Overman and A. K. Sarkar, Tetrahedron Lett., 1992, 33, 4103. H. Arnold, L. E. Overman, M. J. Sharp, and M. C. Witschel, Org. Synth., 1991, 70, 111.
4. L.E. Overman and M. J. Sharp, Tetrahedron Lett., 1988, 29, 901. L.E. Overman, L. A. Robinson, and J. Zablocki, J. Am. Chem. Soc., 1992, 114, 368.
5. L.E. Overman and M. J. Sharp, Tetrahedron Lett., 1988, 29, 901. L.E. Overman, L. A. Robinson, and J. Zablocki, J. Am. Chem. Soc., 1992, 114, 368.
6. 5 η-MeI>5.8 are useful cyclization promoters.
7. R. G. Pearson, H. Sobel, and J. Songstad, J. Am. Chem. Soc., 1968, 90, 319.
8. For representative examples of iminium ion cyclizations under aprotic conditions, see: C. Agami, F. Couty, M. Poursoulis, and J. Vaissermann, Tetrahedron, 1992, 48, 431. T.-K. Yang, S.-M. Hung, D.-S. Lee, A.-W. Hong, and C.-C. Cheng, Tetrahedron Lett., 1989, 30, 4973.
9. For representative examples of iminium ion cyclizations under aprotic conditions, see: C. Agami, F. Couty, M. Poursoulis, and J. Vaissermann, Tetrahedron, 1992, 48, 431. T.-K. Yang, S.-M. Hung, D.-S. Lee, A.-W. Hong, and C.-C. Cheng, Tetrahedron Lett., 1989, 30, 4973.
10. C. Rochin, O. Babot, J. Dunoguès, and F. Duboudin, Synthesis, 1986, 228.
11. H. Heaney, G. Papageorgiou, and R. F. Wilkins, J. Chem. Soc., Chem. Commun., 1988, 1161.
12. 10 gave results similar to those obtained with TMSBr purchased from Aldrich Chemical Co.
13. H. Sakurai, K. Sasaki, and A. Hosomi, Tetrahedron Lett., 1980, 21, 2329.
14. 12
15. Y. Murata, Ph. D. Dissertation, University of California, Irvine, 1995 (available from Dissertation Abstracts).
16. We were unable to obtain this minor product in pure form, therefore the structural assignment is provisional. That this material was likely the (Z)-stereoisomer was consistent with the MS fragmentation pattern (from GC-MS analysis), which was identical to that of 3 (R = Ph).
17. 4), and filtered. Concentration followed by purification of the residue by column