A theoretical study of the mechanism, stereoselectivity and Lewis acid catalyst on the Diels–Alder cycloaddition between furan and activated alkenes

A theoretical study of the mechanism, stereoselectivity, Lewis acid catalysts and solvent effects on the Diels–Alder reactions of methyl acrylate and methyl methacrylate with furan has been carried out through DFT calculations at the B3LYP/6-31G∗ level of theory. Bond order and charge transfer analysis indicate that these reactions take place via an asynchronous concerted mechanism. The Lewis acid catalyst changes the nature of the mechanism but not the stereoselectivity. The inclusion of solvent effects does not change the obtained results in the gas phase study.