Title

Photooxidation of N,N′-Diacylindigo Dyes

Document Type

Article

Publication Date

12-1-1994

Abstract

Irradiation of N,N′-diacylindigo dyes in the presence of oxygen resulted in an unusual oxygen insertion/acyl transfer reaction. While this process occurred over many weeks at room temperature, at 100° C it was complete in a few hours. In some cases the yield of photooxidized product was virtually quantitative. The product structures were proved by spectroscopic methods and in one example by X-ray analysis. A series of mechanistic experiments led to the conclusion that at least the oxygen insertion part of the photooxidation process proceeded via a radical mechanism. The evidence included the following observations: (1) When the photooxidation was conducted in toluene, large amounts of benzyl hydroperoxide were produced; (2) the photooxidation could be achieved in the dark with a radical initiator; (3) attempts to generate the photooxidized product using singlet oxygen chemistry failed. The postulated radical mechanism is described. © 1994, American Chemical Society. All rights reserved.

Journal Title

Journal of Organic Chemistry

Volume

59

Issue

26

First Page

8011

Last Page

8014

DOI

10.1021/jo00105a015

First Department

Chemistry and Biochemistry

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