N-Heterocyclic carbene–palladium catalysts for the direct arylation of pyrrole derivatives with aryl chlorides

Abstract

New Pd–NHC complexes have been synthesized and employed for palladium-catalyzed direct arylation of pyrrole derivatives by using electron-deficient aryl chlorides as coupling partners. The desired coupling products were obtained in moderate to good yields by using 1 mol % of these air-stable palladium complexes. This is an advantage compared to the procedures employing air-sensitive phosphines, which have been previously shown to promote the coupling of aryl chlorides with heteroarenes.

Keywords

• aryl chlorides
• atom-economy
• C–H bond activation
• C–H functionalization
• carbenes
• palladium
• pyrroles