Chemistry Letters, Vol.33, No.10, 1308-1309, 2004
Solvent-free imino-aldol three-component couplings on a conveniently-prepared and reusable phosphoric acid-silica gel support
A new solvent-free procedure for the synthesis of beta-amino carbonyl compounds in generally moderate to excellent yields has been developed. Three-component Mannich-type couplings between aldehydes (aromatic, aliphatic, alicyclic, and heterocyclic), aromatic amines and silyl enol equivalents proceeded smoothly on a conveniently prepared and reusable phosphoric acid-silica gel solid support.