One-step synthesis of spiropyridines, a novel class of C2-symmetric chiral ligands, by cobalt(l)-catalyzed [2 + 2 + 2] cycloadditions between bis-alkynenitriles and alkynes

Organic Letters

Volumn 1, Issue 13, 1999, Pages 2141-2143

  Varela, Jesús A ^a   Castedo, Luis ^a   Saá, Carlos ^a  

^a UNIVERSITY OF SANTIAGO DE COMPOSTELA   (Spain)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0001616654     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol991195m     Document Type: Article

References (25)

1. (a) Noyori, R. Asymmetric Catalysis in Organic Synthesis; Wiley: New York, 1994.
2. (b) Ojima, I., Ed. Catalytic Asymmetric Synthesis; VCH: New York, 1993.
3. Eliel, E. L.; Wilen, S. H. Stereochemistry of Organic Compounds; John Wiley & Sons: New York, 1994; pp 1138-1142.
4. (a) SpirOP ligands: Hu, W.; Yan, M.; Lau, C.; Yang, S. M.; Chan, A. S. C.; Jiang, Y.; Mi, A. Tetrahedron Lett 1999, 40, 973-976 and references therein.
5. (b) Spinol ligands: Birman, V. B.; Rheingold, A. L.; Lam, K. Tetrahedron: Asymmetry 1999, 10, 125-131 and references therein.
6. Spirosilanes: Tamao, K.; Nakamura, K.; Ishii, H.; Yamaguchi, S.; Shiro, M. J. Am. Chem. Soc. 1996, 118, 12469-12470.
7. (a) Stang, P. J. Chem Eur. J. 1998, 4, 19-27 and references therein.
8. (b) Small, J. H.; McCord, D. J.; Greaves, J.; Shea, K. J. J. Am. Chem. Soc. 1995, 117, 11588-11589.
9. Tour, J. M. Chem. Rev. 1996, 96, 537-553.
10. For pioneering work on the synthesis of pyridines by Co(I)-catalyzed [2 + 2 + 2] cycloadditions, see: (a) Wakatsuki, Y.; Yamazaki, H. J. Chem. Soc., Dalton Trans. 1978, 1278-1282 and references therein.
11. (b) Bönnemann, H. Angew. Chem., Int. Ed. Engl. 1978, 17, 505-515 and references therein.
12. (c) Vollhardt, K. P. C. Angew. Chem., Int. Ed. Engl. 1984, 23, 539-556 and references therein.
13. For synthesis of bipyridines and terpyridines using Co(I)-catalyzed [2 + 2 + 2] cycloadditions, see: (a) Varela, J. A.; Castedo, L.; Saá, C. J. Am. Chem. Soc. 1998, 120, 12147-12148.
14. (b) Varela, J. A.; Castedo, L.; Saá, C. J. Org. Chem. 1997, 62, 4189-4192.
15. For preparation of bis-alkynenitrile 1 it was necessary to add 2.5 equiv of NaI. See Supporting Information.
16. Other pressures, whether higher (5.3 bar) or lower (1.2 bar), gave poorer yields of 4a (20% and 9%, respectively).
17. King, R. B.; Treichel, P. M.; Stone, F. G. A. J. Am. Chem. Soc. 1961, 83, 3593-3597.
18. A similar set of conditions has previously been used to prepare pyridines from nitriles and acetylene. See: Chelucci, G. Tetrahedron: Asymmetry 1995, 6, 811-826.
19. All new compounds gave satisfactory analytical and spectroscopic data.
20. R second enantiomer, 22.20 min (Daicel Chiralcel OJ, 90:10 hexane/2-propanol, 0.5 mL/min). First enantiomer: CD (EtOH) λ (nm): 212 (+), 258 (+), 276 (-), 281 (-). Second enantiomer: CD (EtOH) λ (nm): 212 (-), 258 (-), 276 (+), 281 (+).
21. The catalyst was prepared as described by Cammack, J. K.; Jalisatgi, S.; Matzger, A. J.; Negrón, A.; Vollhardt, K. P. C. J. Org. Chem. 1996, 61, 4798-4800.
22. Both 4a and 6 appeared at the beginning of the reaction. To consume all starting material, a substoichiometric amount of catalyst (60%) was necessary.
23. See Supporting Information for experimental details.
24. 2 = H). See ref 8 and Supporting Information.
25. Naiman, A.; Vollhardt, K. P. C. Angew. Chem., Int. Ed. Engl. 1977, 16, 708-709.