Theoretical study of solvent influence on the regiospecificity of the reaction of 3-phenyl-s-tetrazine with ketene-N,N-aminal

Abstract

A theoretical investigation has been performed of the influence of solvent on the regiospecificity of the cycloaddition reaction of 3-phenyl-s-tetrazine with ketene-N,N-aminal. In order to reveal the factors determining the ratio of the two possible isomeric products a combined approach including quantum computation, topological analysis, and algorithm MOPS for associate modeling has been suggested. It has been found that the formation of the meta- product of this reaction is thermodynamically controlled. Formation of the ortho- product is preferred in the cases when association of the tetrazine with solvent leads to covering of the reaction centers. The relationships between the ratio of products and characteristics of "tetrazine-enamine", "tetrazine-solvent", "enamine-solvent", "tetrazine- enamine-solvent" complexes have been investigated.