The photochemical dimerization of 3-heteroaryl-acrylates

Abstract

A detailed explanation of the observed photochemical reactivity of 3-heteroaryl-acrylates is furnished on the basis of a comprehensive review of the photochemical dimerizations of this type of compounds.The reactions occurred in the triplet state of the reagents showing good regio-and stereoselectivities.The regioselectivity can be explained assuming that the dimerization reaction is frontier orbitals controlled.The reaction of the triplet state of a reagent with another molecule of the reagent leads to the formation of the most stable biradical.This behavior induces a control in the relative stereochemistry of the two ester functions.The following cyclization occurs in order to obtain the products under kinetic control.This cyclization allows the formation of the most stable isomers.