Nitrile-forming radical elimination reactions of 1-naphthaldehyde O-(4-substituted benzoyl)oximes activated by triplet benzophenone

Autor:	Koji Yamada, Tetsutaro Igarashi, Kenta Tanaka, Tadamitsu Sakurai, Azusa Wakabayashi, Masaru Sato
Rok vydání:	2006
Předmět:	Nitrile General Chemical Engineering Substituent General Physics and Astronomy General Chemistry Photochemistry Medicinal chemistry Homolysis chemistry.chemical_compound Reaction rate constant chemistry Benzophenone Reactivity (chemistry) Isomerization Bond cleavage
Zdroj:	Journal of Photochemistry and Photobiology A: Chemistry. 183:205-211
ISSN:	1010-6030
DOI:	10.1016/j.jphotochem.2006.03.019
Popis:	It was found that 1-naphthaldehyde O -aroyloximes ( 1 ) preferentially adopting the anti -configuration undergo efficient triplet-sensitized reactions to give 1-cyanonaphthalene and monosubstituted benzenes as unimolecular radical elmination products along with syn - 1 . Negligible formation of 4-substituted benzoic acids strongly suggested the participation of simultaneous N–O and C( O)–Ar bond cleavages in the triplet excited-state anti -isomer. The logarithm of the k r /( k d + k i ) ratio (where k r is the rate constant for homolytic bond cleavage in triplet 1 , k d the rate constant for deactivation of the triplet anti -isomer, and k i is the rate constant for isomerization of triplet anti - 1 into syn - 1 ) used as a measure of the triplet-state reactivity of anti - 1 showed a negligible dependence on the substituent constant and solvent polarity. This finding was explained in terms of a very small contribution of the ionic structure to the transition-state for simultaneous N–O and C( O)–Ar bond cleavages.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::a00ebb4708f22220d14efacf3a70f50f https://doi.org/10.1016/j.jphotochem.2006.03.019 Zobrazit plný text záznamu Full Text from ScienceDirect