The role of pH in the synthesis of diaziridines

The greatest yield in the synthesis of diaziridines from carbonyl compounds, amines, and aminating reagents in water is achieved at a specific pH, which shifts to less alkaline values with increasing -I effect of the substituents in the carbonyl compound and with decreasing pK_BH⁺ value of the amine. The role of pH is related to the conditions for the generation of an immonium from the intermediatea-aminocarbinol. The nuclear Overhauser effect was used to determine the orientation of the substituents in several diastereomers of the didikyldiaziridines obtained.