Accessing meta-Enone-Substituted Anisoles using ArN2BF4 as Precatalyst via Rearrangement of Alkyne-Tethered Cyclohexadienones

Abstract A method for the rearrangement of alkyne-tethered cyclohexadienone to furnish meta-enone-substituted anisoles using arene diazonium tetrafluoroborate salts as precatalyst was developed. The reaction proceeds via intramolecular 1,6-enyne cyclization-aromatization and oxetene ring opening. The same protocol was also employed to obtain phthalide-substituted anisoles. The reactions are atom economic, have a broad substrate scope and amenable to gram-scale synthesis. Further synthetic transformations of the products were also performed.