Aryloxy Radicals from Diaryloxydiazirines: α-Cleavage of Diaryloxycarbenes or Excited Diazirines?

Organic Letters

Volumn 5, Issue 26, 2003, Pages 5027-5030

  Fedé, Jean Marie ^a   Jockusch, Steffen ^b   Lin, Nan ^a   Moss, Robert A ^a   Turro, Nicholas J ^b  

^a RUTGERS UNIVERSITY   (United States)

^b Och Spine at New York Presbyterian Hospitals   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

AZIRINE DERIVATIVE; CARBENOID; RADICAL;

ARTICLE; CHEMICAL REACTION; PHOTOLYSIS; REACTION ANALYSIS; SYNTHESIS; TEMPERATURE SENSITIVITY; ULTRAVIOLET SPECTROSCOPY;

EID: 0347916939     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol030123z     Document Type: Article

References (36)

1. (a) Hoffmann, R. W. Acc. Chem. Res. 1985, 18, 248.
2. (b) Hoffmann, R. W.; Reiffen, M. Chem. Ber. 1976, 109, 2565.
3. (c) Lemal, D. M.; Gosselink, E. P.; McGregor, S. D. J. Am. Chem. Soc. 1966, 88, 582.
4. (d) Moss, R. A.; Wlostowski, M.; Shen, S.; Krogh-Jespersen, K.; Matro, A. J. Am. Chem. Soc. 1988, 110, 4443.
5. (e) El-Saidi, M.; Kassani, K.; Pole, D. L.; Tadey, T.; Warkentin, J. J. Am. Chem. Soc. 1992, 114, 8751.
6. (f) For further applications, see: Warkentin, J. In Advances in Carbene Chemistry; Brinker, U. H., Ed.; JAI Press: Stamford, CT, 1998; Vol. 2, esp. pp 256f and references cited there.
7. (a) Lu, X.; Reid, D. L.; Warkentin, J. Can. J. Chem. 2001, 79, 319.
8. (b) Oxadiazolines do not generally afford carbenes on photolysis. Private communication from Prof. J. Warkentin, 1 Oct 2003.
9. Vorwinkel, E.; Baese, H.-J. Chem. Ber. 1974, 107, 1213.
10. See the appropriate table in the Supporting Information for spectroscopic data. Experimental details appear in: Fedé, J.-M. Ph.D. Dissertation, Rutgers University, New Brunswick, NJ, 2003.
11. Grigat, E.; Pütter, R.; König, C. Chem. Ber. 1965, 98, 144.
12. Graham, W. H. J. Am. Chem. Soc. 1965, 87, 4396.
13. Moss, R. A.; Perez, L. A.; Wlostowska, J.; Guo, W.; Krogh-Jespersen, K. J. Org. Chem. 1982, 47, 4177.
14. Moss, R. A. In Chemistry of Diazirines; Liu, M. T. H., Ed.; CRC Press: Boca Raton, 1987; Vol. I, pp 99f. Moss, R. A.; Wlostowski, M.; Terpinski, J.; Kmiecik-Lawrynowicz, G.; Krogh-Jerspersen, K. J. Am. Chem. Soc. 1987, 109, 3811.
15. Moss, R. A. In Chemistry of Diazirines; Liu, M. T. H., Ed.; CRC Press: Boca Raton, 1987; Vol. I, pp 99f. Moss, R. A.; Wlostowski, M.; Terpinski, J.; Kmiecik-Lawrynowicz, G.; Krogh-Jerspersen, K. J. Am. Chem. Soc. 1987, 109, 3811.
16. Al Sabbagh, M. M.; Calmon, M.; Calmon, J.-P. Bull. Soc. Chim. Fr. 1983, Part II, 73.
17. About 5-10% of triaryl orthoformate formed during the synthesis of 7 and could not be separated by chromatography.
18. 4-OH with di-tert-butyl peroxide. Spectroscopic properties were in agreement with literature data: Maumy, M.; Capdevielle, P. Bull. Soc. Chim. Fr. 1995, 132, 734.
19. 1 absorptions at 298-302 nm for carbenes 8a-d in the gas phase. We thank Professor Karsten Krogh-Jespersen for these calculations.
20. Das, P. K.; Encinas, M. V.; Steenken, S.; Scaiano, J. C. J. Am. Chem. Soc. 1981, 103, 4162.
21. Errors in the absolute rate constants are estimated at 10-20%.
22. Foti, M.; Ingold, K. U.; Lusztyk, J. J. Am. Chem. Soc. 1994, 116, 9440.
23. • from LFP of 7a was quenched by ascorbyl palmitate, but the UV signal was too weak for good kinetics.
24. Platz, M. S. In Advances in Carbene Chemistry; Brinker, U. H., Ed.; JAI Press: Stamford, CT, 1998; Vol. 2, pp 133f.
25. (a) Glick, H. C.; Likhotvorik, I. R.; Jones, M., Jr., Tetrahedron Lett. 1995, 36, 5715.
26. (b) Thamattoor, D. M.; Jones, M., Jr.; Pan, W.; Shevlin, P. B. Tetrahedron Lett. 1996, 37, 8333.
27. (c) Nigam, M.; Platz, M. S.; Showalter, B. M.; Toscano, J. P.; Johnson, R.; Abbot, S. C.; Kirchhoff, M. M. J. Am. Chem. Soc. 1998, 120, 8055.
28. Merrer, D. C.; Moss, R. A. In Advances in Carbene Chemistry; Brinker, U. H., Ed.; Elevier: Amsterdam, 2001; Vol. 3, pp 53f.
29. (a) Merkley, N.; El-Saidi, M.; Warkentin, J. Can. J. Chem. 2000, 78, 356.
30. (b) Merkley, N.; Warkentin, J. Can. J. Chem. 2000, 78, 942.
31. (c) Venneri, P. C.; Warkentin, J. J. Am. Chem. Soc. 1998, 120, 11182.
32. We thank Professor Ronald R. Sauers for these B3LYP/6-31G(d) calculations.
33. Alternatively, the excited state of the diazirine could yield an electronically excited state of the carbene which could undergo α-fragmentation if the excitation energy exceeds ∼60 kcal/mol.
34. •.
35. Alternatively, at 90 K, 13 partitions almost exclusively to carbene 8.
36. A referee has pointed out that if diaryloxycarbenes were prone to fragmentation, it would more likely occur when the diazirine was thermally decomposed, rather than photolyzed in solution, given rapid vibrational cooling.