Heteropoly Acids Catalyzed Direct Mannich Reactions: Three-Component Synthesis of N-Protected β-Amino Ketones.

Heteropoly acids efficiently catalyzed one-pot three-component Mannich reactions of aryl aldehydes, aryl ketones, and carbamates at ambient temperature and afforded the corresponding N-protected β-amino ketones in good to excellent yields. This method provides a novel and improved modification of three-component Mannich reactions in terms of a wide scope of aldehydes, ketones and carbamates, economic viability and reusability. [ABSTRACT FROM AUTHOR]