New structural aspects of 3-vinyl-1H-indoles for predicting the outcome of Diels-Alder reactions

Some selected 3-vinyl-1H-indoles have been synthesised and the first13C-NMR studies performed; in addition He(Iα) photoelectron spectra and the results of perturbation MO calculations of some examples of this class of compounds are presented. The molecular characteristics obtained thereby can be used to predict the results of [π4s+π2s]-cycloaddition reactions with 3-vinylindoles.