Alcohol Mediated Isocyanide Domino Reactions Toward 2-Aminofuronaphthoquinones

Abstract

An unprecedented alcohol mediated formation of 2-amino-naphtho[2,3-b]furan-4,9-dione derivatives from 2-hydroxy-1,4-naphthoquinones and isocyanides under microwave irradiation in the presence of Yb(OTf)3 is reported. The effect of different alcohol media, isocyanides and substituted naphthoquinones on the reaction was investigated. A plausible mechanism of this domino transformation implies a conjugated addition of the alcohol to the naphthoquinone to generate an ether intermediate, followed by an isocyanide addition and evolution of the corresponding intermediate by intramolecular cyclization. This methodology represents an alternative approach for the access to this interesting kind of compounds.