(±)-Camphor-10-sulfonic acid catalyzed direct one-pot three-component Mannich type reaction of alkyl (hetero)aryl ketones under solvent-free conditions: application to the synthesis of aminochromans

Abstract

Direct three-component Mannich type reactions of (hetero)aromatic ketones with aromatic aldehydes and aromatic amines were efficiently catalyzed by camphor-10-sulfonic acid at ambient temperature under solvent free conditions to afford β-amino ketones in good to excellent yields. Syntheses of aminochromans were accomplished from one of the Mannich adducts via an unprecedented route involving intramolecular etherification with CuI/8-hydroxyquinoline.