Stereoselectivity and regioselectivity in Diels–Alder reactions studied by intermolecular perturbation theory
Diels–Alder reactions of ethene, acrolein and acrylonitrile with butadiene and its 1-methyl, 2-methyl and 2-cyano derivatives have been studied by self-consistent field intermolecular perturbation theory. The procedure is successful in reproducing the stereochemical predictions of other theoretical techniques, and provides a way to analyse the contributions to the interaction energy and to gain theoretical insight into the effects responsible for stereoselectivity. It is less successful, however, in predicting regiochemical preferences for these reactions. Possible reasons for this are discussed.