Products and mechanisms of photochemical transformations of o-quinones
作者:M. P. Shurygina、Yu. A. Kurskii、N. O. Druzhkov、S. A. Chesnokov、G. A. Abakumov
DOI:10.1134/s0018143910030148
日期:2010.5
The photochemicaltransformations of quinones by the action of light at λ > 500 nm, namely, the photodecarbonylation and photoreduction reactions were studied with the use of a series of o-benzoquinones and 9,10-phenanthrenequinone as examples. The two-stage mechanism of the decarbonylation reaction of o-benzoquinones was established. At the first stage, rearrangement of a photoexcited quinone molecule
Photooxygenolysis of 3,6-di-tert-butyl-o-benzoquinone
作者:V. B. Vol’eva、I. S. Belostotskaya、N. L. Komissarova、Z. A. Starikova、L. N. Kurkovskaya
DOI:10.1134/s1070428002120114
日期:2006.2
The photolysis of 3,6- and 3,5-di-tert-butyl-o-benzoquinones in benzene (lambda > 380 nm, inert atmosphere) involves decarbonylation of the compounds to furnish respectively 2,5- and 2,4-di-tert-butylcyclopentadienones. The 2,5-isomer is stable, and the 2,4-di-tert-butylcyclopentadienone suffers a conversion into a Diels-Alder adduct. The participation of oxygen inhibited the decarbonylation and changed the direction of the photolysis: Here the products of the 3,5-di-tert-butyl-o-benzoquinones conversion were a di-tert-butylmuconic anhydride and dipivalylethylene. It was concluded that a singlet oxygen was involved in the process which formed by a triplet-triplet annihilation at the interaction of O-3(2) with a triplet-excited initial quinone.