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The regioselective [2 + 2] photocycloaddition reaction of 2-(3,4-dimethoxystyryl)quinoxaline in solution
Olga A Fedorova1, Alina E Saifutiarova1, Elena N Gulakova2
1A. N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences, 119991, Vavilova str. 28, Moscow, Russia. fedorova@ineos.ac.ru and D. Mendeleev University of Chemical Technology of Russia, 125047, Miusskaya sqr. 9, Moscow, Russia.
Abstract:
Herein, the [2 + 2] photocycloaddition between two molecules of (E)-2-(3,4-dimethoxystyryl)-quinoxaline (1) in an acetonitrile solution to form only one cyclobutane isomer out of eleven possible isomers is described. The observed photocycloaddition reaction is reversible; thus, the studied photocycloaddition reaction can be considered as a photoreversible photochromic process. The removal of two methoxy groups from the (E)-2-(3,4-dimethoxystyryl)quinoxaline (1) structure produces compound 2, which participates only in the photoisomerization reaction. The change of the quinoxaline residue in 1 to quinoline results in the formation of compound 3, which demonstrates the regioselective oxidization electrocyclic transformation through the formation of a novel C-N bond.
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