Advances in vicinal dicarbo-C–H-functionalization of five-membered heteroarenes via palladium/norbornene cooperative catalysis

Abstract

Direct introduction of two carbon substituents to less functionalized aromatic cores has been an attractive objective for late-stage modification and streamlined synthesis of complex molecules. Using the palladium/norbornene (Pd/NBE) cooperative catalysis, while initial achievements on double CH functionalization were made in the past, the scopes of reactions and substrates remain to be expanded. Here we report some new advances on the Pd/NBE-catalyzed dicarbofunctionalization of five-membered heteroarenes through sequential CH activation. These efforts include the Pd/NBE-catalyzed C4-arylation/C5-alkenylation of diverse furans, the first C4-alkynylation of thiophenes/pyrroles, and the preliminary C4-methylation.

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