Construction of 4-Acyl-2-quinolones through Sc(OTf)3-Catalyzed Ring-Closing Alkyne-Carbonyl Metathesis

An atom-economical protocol to construct densely substituted 4acyl-2-quinolones from N-(2-alkynylphenyl)-alpha-ketoamides has been developed through Sc(OTf)3-catalyzed ring-closing alkyne-carbonyl metathesis. Mechanistic experimental studies support that coordinative interaction between Sc(OTf))3 and the substrate, the formation of an oxetene intermediate, and an electrocyclic ring-opening of the oxetene might be involved.

Automated summary

An atom-economical protocol utilizing Sc(OTf)3 as the catalyst has been developed to synthesize densely substituted 4acyl-2-quinolones. Mechanistic experimental studies suggest the involvement of coordinative interaction between Sc(OTf)3 and the substrate, formation of an oxetene intermediate, and an electrocyclic ring-opening of the oxetene.