L-Proline catalysed multicomponent synthesis of 3-amino alkylated indoles via a Mannich-type reaction under solvent-free conditions

An efficient L-proline catalyzed one-pot synthesis of 3-amino-alkylated indoles has been developed via a three-component Mannich-type reaction viz. secondary amines, aldehyde and indoles under solvent-free conditions at room temperature. Several amino acids (acidic, basic and neutral) have been screened for the reaction but the best results were obtained with L-proline.