Bioinspired construction of a spirocyclohexadienone moiety via sodium nitrite catalyzed aerobic intramolecular oxidative phenol coupling.

An efficient and green intramolecular oxidative phenol coupling for the direct construction of spirocyclohexadienones has been developed, which uses environment-friendly sodium nitrite as the catalyst and oxygen in the air as the terminal oxidant. Hydroxy-containing substituted phenanthrenes and dibenzoazepines could be easily obtained from the dienone-phenol rearrangement.