Benzofuran and benzofuranone derivatives have been synthesized through exclusive 5-exo-digintramolecular hydroarylation using the amide-directed, cost-effective, high-valent Cp*CoIII-catalytic system.Challenging one-pot, orthogonal CH functionalizations using two different electrophiles are also reported toafford polysubstituted benzofurans. Several valuable functional group interconversions along with removal ofthe amide directing group provide a route to access several diversely functionalized benzofurans. Themechanistic study suggests a reversible cobaltation step is operative here.
Title: Cobalt(III)-Catalyzed Construction of Benzofurans, Benzofuranones and One-Pot Orthogonal C−H Functionalizations to Access Polysubstituted Benzofurans
Journal: Adv. Synth. Catal. 2018, 360, 2204 –2210