Gold-Catalyzed Carbocyclization/C=N Bond Formation Cascade of Alkyne-Tethered Diazo Compounds with Benzo[c]isoxazoles for the Assembly of 4-Iminonaphthalenones and Indenes

A gold-catalyzed carbocyclization/C=N bond formation cascade reaction has been developed for the synthesis of polyfunctionalized 4-iminonaphthalenones and indenes in good to high yields under mild reaction conditions. The reaction goes through 5/6-endo-dig diazo-yne carbocyclization to form the endocyclic vinyl carbene species from corresponding alkyne-tethered diazo compounds, followed by electrophilic addition/N-O bond cleavage/aromatization sequence with benzo[c]isoxazoles, which features a C=N bond formation process. In addition, the resulting products could be converted into multi-substituted 2-naphthol derivatives in high yields.

Automated summary

A gold-catalyzed carbocyclization/C=N bond formation cascade reaction has been developed for the synthesis of polyfunctionalized 4-iminonaphthalenones and indenes in good to high yields under mild reaction conditions. The resulting products could be converted into multi-substituted 2-naphthol derivatives in high yields.