Four-component reaction between naphthols, substituted β-nitrostyrenes, substituted benzaldehydes and ammonium acetate in water–PEG-400: an approach to construct polysubstituted naphthofuranamines

Abstract

An eco-friendly straightforward and efficient one-pot four-component protocol has been developed for the synthesis of naphtho[b]furan scaffolds in water–PEG-400 (6 : 1, v/v) at 80 °C from naphthanols, substituted β-nitrostyrenes, substituted benzaldehydes and ammonium acetate. The new efficient domino reaction formed a furan ring and a Schiff base core by the concomitant formation of C–C, C–O, and C–N multiple bonds presumably involving a sequence of a Michael reaction, aza–ene reaction, imine–enamine/keto–enol tautomerization, O-cyclization and aromatization as key steps.