Versatile photochemical reactivity of diverse substituted 2-, 4- and 5-(o-vinylstyryl)oxazoles (CROSBI ID 244776)
Prilog u časopisu | izvorni znanstveni rad | međunarodna recenzija
Podaci o odgovornosti
Šagud, Ivana ; Šindler-Kulyk, Marija ; Vojnović-Jandrić, Dragana ; Marinić, Željko
engleski
Versatile photochemical reactivity of diverse substituted 2-, 4- and 5-(o-vinylstyryl)oxazoles
To study the effects of the position of the hexatrienyl moiety on the oxazole ring, novel substituted cis/trans-2/4/5-(2-vinylstyryl)oxazoles have been synthesized. These novel compounds were prepared by Wittig reaction from diphosphonium salt of a, a’-o-xylenedibromide, formaldehyde and the corresponding 2-methyl-4-, 4-methyl-2-, 2-pheny-5- and 4-methyl-5-oxazolecarbaldehyde, respectively. Aldehydes were synthesized by several synthetic approaches. By intramolecular photocycloaddition 2-methyl-4-(2-vinylstyryl)oxazole afforded, as major product, fused oxazoline-benzobicyclo[3.2.1]octene with small quantities of 4-(1, 2-dihydronaphthalen-2-yl)-2-methyloxazole, as electrocyclization product. Upon irradiation of 4-methyl-5-(2-vinylstyryl)oxazole endo- and exo-benzobicyclo[2.1.1]hexene products were formed by [2+2] cycloaddition and this was the first instance of the 1, 4-closure to the bicyclo[2.1.1]hexene skeleton in the 2-, 4-, and 5-oxazole-stilbene derivatives studied so far. Derivatives, 2-phenyl-5- and 4-methyl-2-(2-vinylstyryl)oxazole do not react and give only high weight molecular products but are crucial as a comparison in the overall mechanistic study. We have found that depending on the position of the hexatrienyl moiety in the oxazole ring, as well as the position of the methyl/phenyl substituents these new vinylstyryl-2/4/5-oxazole derivatives show diverse photochemical behavior.
benzobicyclo[3.2.1]octene ; intramolecular photocycloaddition ; oxazoline ; vinylstyryl
nije evidentirano
nije evidentirano
nije evidentirano
nije evidentirano
nije evidentirano
nije evidentirano
Podaci o izdanju
28 (4)
2018.
515-524
objavljeno
1434-193X
1099-0690
10.1002/ejoc.201701551