Intermolecular interactions that determine the regioselectivity in 1,3‐dipolar cycloadditions of N‐methyl‐1,3‐oxazolium‐5‐olates with N‐(phenylmethylene)benzenesulphonamide

1,3‐Dipolar cycloadditions of N‐(phenylmethylene)benzenesulphonamide with mesionic N‐methyl‐1,3‐oxazolium‐5‐olates give 2,5‐disubstituted imidazole derivatives with high regioselectivity. The intermolecular interactions underlying this regioselectivity were investigated. The conformational and electronic properties of the reagents were characterized separately. The approach in the early stages of the reactions was then modelled by considering the steric and electrostatic molecular interactions. The interaction energies related to different reaction paths were calculated by perturbation molecular orbital (PMO) treatment and compared