Heterolytic cleavage of a β-phosphatoxyalkyl radical resulting in phosphate migration or radical cation formation as a function of solvent polarity

Organic Letters

Volumn 1, Issue 1, 1999, Pages 153-156

  Whitted, Patrick O ^a   Horner, John H ^a   Newcomb, Martin ^a   Huang, Xianhai ^b   Crich, David ^b  

^a WAYNE STATE UNIVERSITY   (United States)

^b UNIVERSITY OF ILLINOIS AT CHICAGO   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

CATION; FREE RADICAL; ORGANOPHOSPHATE; SOLVENT;

ARTICLE; CHEMISTRY; KINETICS; PHOTOLYSIS; PHYSICAL CHEMISTRY; ULTRAVIOLET SPECTROPHOTOMETRY;

CATIONS; CHEMISTRY, PHYSICAL; FREE RADICALS; KINETICS; PHOSPHORIC ACID ESTERS; PHOTOLYSIS; SOLVENTS; SPECTROPHOTOMETRY, ULTRAVIOLET;

EID: 0033564989     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol990054h     Document Type: Article

References (20)

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7. Newcomb, M.; Horner, J. H.; Whitted, P. O.; Crich, D.; Huang, X.; Yao, Q.; Zipse, H. Submitted for publication.
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9. Chatgilialoglu, C. In Handbook of Organic Photochemistry; Scaiano, J. C., Ed.; CRC Press: Boca Raton, FL, 1989; Vol. 2; pp 3-11.
10. The acid precursor to PTOC ester 5 was prepared by a reaction sequence similar to that employed previously for production of the normethoxy analogue (see ref 8). The synthetic intermediates and the carboxylic acid had appropriate NMR spectra and elemental analyses, and PTOC ester 5 had appropriate NMR spectra.
11. This procedure was used previously to obtain a UV spectrum of a benzylic radical from a PTOC ester precursor and is described in more detail in ref 8.
12. Johnston, L. J.; Schepp, N. P. J. Am. Chem. Soc. 1993, 115, 6564-6571.
13. Radical cation 4 also displayed an expected (ref 13) broad absorbance at longer wavelengths; spectra to 700 nm are in Supporting Information.
14. -1 as determined from oxidation of the styrene with the chloranil triplet and comparison of the signal intensities for 4 and the chloranil radical anion.
15. We note, however, that this behavior only excludes a relatively slow secondary reaction as the source of one product. It does not exclude the possibility that two distinct reactions give rise to products 3 and 4 because the kinetics are only reporting the total rate of loss of reactant radical 1, irrespective of the number of reaction channels available.
16. Reichardt, C. Chem. Rev. 1994, 94, 2319-2358. Skwierczynski, R. D.; Connors, K. A. J. Chem. Soc., Perkin Trans. 2 1994, 467-472.
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18. The oxidation potential of p-methoxystyrene is ∼0.4 V lower than that of styrene; see: Akbulut, U.; Toppare, L.; Türker, L. Mȧkromol. Chem. 1983, 184, 1661-1667.
19. For example, ethyl vinyl ether and styrene have the same oxidation potentials in acetontrile. See: Katz, M.; Riemenschneider, P.; Wendt, H. Electrochim. Acta 1972, 17, 1595-1607.
20. Zipse, H. J. Am. Chem. Soc. 1997, 119, 2889-2893.