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-(phenyl methylene)benzenesulphonamide with mesoionic N-methyl-1,3-oxazolium-5-olates give 2,5-disubstituted imidazole derivatives with high regioselectivity, The intermolecular i nteractions underlying this regioselectivity were investigated, The co nformational and electronic properties of the reagents were characteri zed separately, The approach in the early stages of the reactions was then modelled by considering the steric and electrostatic molecular in teractions, The interaction energies related to different reaction pat hs were calculated by perturbation molecular orbital (PMO) treatment a nd compared.