L-proline catalyzed unprecedented synthesis of novel naphtho-bis[1,3]oxazines under solvent-free conditions

Abstract

An unprecedented l-proline-mediated one-pot sequential synthesis of novel 3,10-diphenyl-2,3,4,9,10,11-hexahydronaphtho[1,2-e:4,3-e′]bis[1,3]oxazine derivatives from 2,3-dihydroxynaphthalene, formaldehyde, and anilines under solvent-free conditions has been reported. Under the optimized reaction conditions, a broad range of substituted anilines and 2,3-dihydroxynaphthalene were found to participate in this transformation, thus affording new 3,10-diphenyl-2,3,4,9,10,11-hexahydronaphtho[1,2-e:4,3-e′]bis[1,3]oxaz-ines in good to excellent yields. This green procedure offers several advantages such as high atom economy, mild reaction conditions, short reaction time, easy workup and column chromatography-free method with a wide range of functional group tolerance.

Graphical Abstract

Keywords:

• Multicomponent reaction
• naphtho-bis[13]oxazines
• one-pot synthesis
• polyheterocycles