Stepwise or concerted? A DFT study on the mechanism of ionic Diels-Alder reactions of chromanes

Abstract

The stepwise and concerted ionic Diels-Alder reactions between phenyl(pyridin-2-ylmethylene)oxonium and styrene derivatives were explored theoretically. The results support the use of a computational method via persistent intermediates. The DFT method was essential to reproduce a reasonable potential energy surface for these challenging systems.