One-pot three-component kinetic controlled and syn-diastereoselective Mannich reaction of unfunctionalized ketones in water catalyzed by nano-manganese hydrogen sulfate particles

Abstract

Direct catalytic three component Mannich reaction of aliphatic ketone, aldehyde and amine was described in the presence of a catalytic amount of nano-Mn(HSO4)2 (10 mol%) and a surfactant, for example sodium dodecyl sulfate (10 mol%) in the water as a green solvent. β-amino carbonyl compounds were obtained regioselectively as a less-substituted product from a one-pot three component Mannich reaction of 2-butanone in the above conditions. On the other hand, 3-pentanone as a symmetric ketone in the Mannich reactions gave β-amino carbonyl compounds with moderate to high syn diasterioselectivity. Control of regioselectivity and/or diasterioselectivity of the most products is related to micelle formation of organic substrates and SDS in water. Hydrophobic groups of substrates self-assembled in these microreactors whereas, hydrophilic groups were solvated with water or chelated with Mn(HSO4). The above interactions forwarded to these observed selectivity.