Theoretical study of the mechanism and regioselectivity of the 1,3-dipolar cycloaddition of diazomethane with methyl acrylate using theoretical approaches

In this work, the mechanism and regioselectivity of the 1,3-dipolar cycloaddition of diazomethane with methyl acrylate are studied using several quantum chemistry approaches. Potential energy surface analysis and IRC calculations show that this cycloaddition follows an asynchronous concerted mechanism through the ortho channel. The favored cyclization mode and the experimental regioselectivity of this cycloaddition are rationalized by both activation energy calculations, FMO model, and philicity indexes derived from density functional theory. The calculations are performed at the B3LYP/6-31G(d) level of theory and the obtained results are in agreement with experimental outcomes. (C) 2008 Elsevier B.V. All rights reserved.