One-Pot Synthesis of β-Amino Ketones via Direct Mannich-type Reaction Catalyzed with CuFe2O4@SO3H

Mannich reactions are among the most important carbon–carbon bond forming reactions inorganic synthesis. They provide β-amino carbonyl compounds, which are important syntheticintermediates for various pharmaceuticals and natural products [1]. Therefore, the developmentof new synthetic methods leading to β-amino carbonyl compounds or their derivativeshas attracted much attention. However, the classic Mannich reaction has limited applications.Attempts have been made in the past to improve methodologies based on two-component reactions,where the imine as electrophile is formed and then reacted with nucleophiles such asenolates, enol ethers, and enamines [2]. However, in most cases these protocols use hazardousorganic solvents, costly and non-recoverable catalysts, and requirement of special effort forcatalyst preparation, and suffer from long reaction time with low yields [3]. Therefore, thedevelopment of modern versions of the reaction that work under mild conditions is of greatimportance. CuFe2O4@SO3H is an excellent acidic catalyst, which is frequently used to promotesome important reactions. We report herein full details of a novel, convenient, and simpleprocedure to realize a one-pot three-component reaction of aldehydes, amines, and ketones,catalyzed by CuFe2O4@SO3H, for the preparation of β-amino carbonyl compounds inEtOH.