Facile imine synthesis under green conditions using Amberlyst® 15

Abstract

Imines and their derivatives are of great interest to organic synthetic chemists due to their involvement as key intermediates which facilitate the construction of nitrogen heterocycles, particularly the formation of alkaloids. Imine formation by condensation of primary amines with aromatic aldehydes and cyclohexanone has been investigated under environmentally-friendly solventless heterogeneous catalysis. An array of different imines was obtained in excellent yields in appreciably short reaction times using Amberlyst® 15 as a heterogeneous catalyst. The latter was used owing to its high commercial availability, recyclability, ease of separation from the reaction mixture, and versatility.

Utilizing the Imine Condensation in Organic Chemistry Teaching Laboratories to Reinforce Steric Effects, Electronic Effects, and Green Chemistry Principles

“…20 Heterogeneous catalysts have also been used in solvent free conditions with various desiccants in order to analyze activity and efficiency for the imine condensation. 21 However, even with these recent advances, green chemistry with regard to the imine condensation reaction is rarely taken into consideration in the sophomore laboratory setting. The imine condensation used in this laboratory project was adapted from Troisi and colleagues in which aromatic aldehydes and primary alkyl amines are stirred for 1.5 h in anhydrous diethyl ether in the presence of molecular sieves to produce the corresponding imine.…”

“…In some cases, water or fruit juice can be used as a solvent, , microwave radiation can be used as an energy source, or silica can be used as a catalyst in these reactions . Heterogeneous catalysts have also been used in solvent free conditions with various desiccants in order to analyze activity and efficiency for the imine condensation . However, even with these recent advances, green chemistry with regard to the imine condensation reaction is rarely taken into consideration in the sophomore laboratory setting.…”