[BCMIM][Cl] ionic liquid catalyzed diastereoselective synthesis of β‐amino ketones via facile, one‐pot, multicomponent Mannich reaction under solvent‐free condition

Abstract In this work, by utilizing 6 mol% of 1,3‐bis(carboxymethyl)imidazolium chloride [BCMIM][Cl] ionic liquid as a catalyst, a highly effective diastereoselective one‐pot multicomponent Mannich reaction has been established. The three components, namely, cyclohexanone, substituted aromatic aldehydes, and substituted aromatic amines, underwent the Mannich reaction efficiently under the solvent‐free condition at room temperature in the presence of 6 mol% [BCMIM][Cl] catalyst to afford the desired β‐amino ketones. Excellent diastereoselectivity, rapid reaction times, high yields, and no purification by column chromatography are the key characteristics of this process. All synthesized derivatives were thoroughly characterized and confirmed using 1 H NMR, 13 C NMR, and Fourier‐transform infrared spectral methods. Moreover, the catalytic activity of the [BCMIM][Cl] ionic liquid catalyst was maintained after being reprocessed and used three times.