1,3-Dipolar cycloaddition or nucleophilic addition: Influence of solvents and nature of substituents in the reagent and substrate molecules on the reaction of 4,5-dihydro-1H-imidazole 3-oxides with alkynes

摘要

Two competitive processes - 1,3-dipolar cycloaddition and nucleophilic addition - in the reaction of 4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole 3-oxides with asymmetrically substituted alkynes were shown to occur. The influence of solvents and the nature of substituents in the reagent and substrate molecules on the rate ratio of these competitive processes were studied.