A DFT study of the role of Lewis acid catalysts in the mechanism of the 1,3-dipolar cycloaddition of nitrile imines towards electron-deficient acryloyl derivatives

► We have studied the role of Mg complex in the regioselectivity of the 13DC reactions. ► The reactions have an asynchronous concerted mechanism with a low polar character. ► The steric repulsion plays an important role to display a high C regioselectivity. ► In dichloromethane, the reaction profiles are similar to those obtained in gas phase.