All That metas─Synthesis of Dispersion Energy Donor-Substituted Benzenes.

We report a general and scalable method for the synthesis of all-meta-trisubstituted benzenes from readily available 3,5-disubstituted catechols. Oxidation and [4 + 2] cycloaddition with acetylene dienophiles generate a bicyclo[2.2.2]octane structure that is doubly decarbonylated initiated by blue-light irradiation, leading to a meta,meta-disubstitution pattern on the re-aromatized system. This enables this substitution pattern even with very bulky alkyl groups (deemed excellent dispersion energy donors) to be incorporated into, for example, chiral phosphoric acid catalysts.