Exploration of regiospecificity phenomenon in [2+3] cycloaddition reactions between arylnitrones and trans-substituted nitroethenes on the basis of the reactivity indices theory

Analysis of global electrophilicity and nucleophilicity power of the addends indicate polar character of [2+3] cycloaddition reactions between arylnitrones and trans-substituted nitroethenes. The regioselectivity of these reactions is determined by nucleophilic attack of oxygen atom from nitrone on activated ?-position of nitroalkene. Interaction of this type leads to 4-nitroisoxazolidines, which are the only reaction products.