Cyclopenta[b]pyrroles from triazines: synthetic and mechanistic studies

Organic Letters

Volumn 12, Issue 1, 2010, Pages 164-167

  Ye, Long ^a   Haddadin, Makhluf J ^b   Lodewyk, Michael W ^a   Ferreira, Andrew J ^a   Fettinger, James C ^a   Tantillo, Dean J ^a   Kurth, Mark J ^a  

^a UNIVERSITY OF CALIFORNIA   (United States)

^b AMERICAN UNIVERSITY OF BEIRUT   (Lebanon)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 73949154046     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol902559u     Document Type: Article

References (24)

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3. (c) Boger, D. L.; Weinreb, S. N. Hetero Diels-Alder Methodology in Organic Synthesis; Academic Press: New York, 1987;
4. Organic Chemistry Monograph Series, Vol.47.
5. (d) Kametani, T.; Hibino, S. In Advances in Heterocyclic chemistry; Katritzky, A. R., Ed.; Academic Press: New York, 1987; Vol.42, p 246.
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11. (a) Sakya, S. M.; Groskopf, K. K.; Boger, D. L. Tetrahedron Lett. 1997, 38, 3805.
12. (b) Saracoglu, N. Tetrahedron 2007, 63, 4199.
13. (c) Geyelin, P. H.; Raw, S. A.; Taylor, R. J. K. Arkivoc 2007, 37.
14. (a) Haddadin, M. J.; Agha, B. J.; Salka, M. S. Tetrahedron Lett. 1984, 25, 2577.
15. (b) Robins, L. I.; Carpenter, R. D.; Fettinger, J. C.; Haddadin, M. J.; Tinti, D. S.; Kurth, M. J. J. Org. Chem. 2006, 71, 2480.
16. Lodewyk, M. W.; Kurth, M. J.; Tantillo, D. J. J. Org. Chem. 2009, 74, 4801.
17. (a) Suen, Y. F.; Hope, H.; Nantz, M. H.; Haddadin, M. J.; Kurth, M. J. Tetrahedron Lett. 2006, 47, 7893.
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19. Dry chloroform (1 mL) and 3 Å molecular sieves were added to a mixture of pyrrolidine (22 μL, 0.26 mmol) and cyclobutanone (320 μL, 4.3 mmol) in a sealable thick-wall test tube. Triazine 9a (200 mg, 0.86 mmol) was then added to the above solution after it was stirred for 10 min. After bubbling stopped, the tube was sealed, and the reaction was stirred at 60 °C for 3-5 h and monitored by LC/MS.
20. 4, followed by chromatographic purification (silica gel with gradient hexane/ethyl acetate elution).
21. Konno, S.; Ohba, S.; Sagi, M.; Yamanka, M. Chem. Pharm. Bull. 1987, 35, 1378.
22. 5
23. Note here that additional calculations (see Supporting Information) revealed that structure 15 (X = O) is at least 20 kcal/mol lower in energy than neutral tautomers of structure 12.
24. See Supporting Information for discussion related to this same possibility for the tetrazine-derived systems studied in ref 5.