Direct C2-arylation of N-acyl pyrroles with aryl halides under palladium catalysis

Abstract

C2-arylation of N-acyl pyrroles with aryl halides is developed for the first time using Pd(PPh₃)₄ as a catalyst in combination with Ag₂CO₃ under air, which allowed the application of a good compatibility catalytic system. This protocol provides a straightforward method for the preparation of valuable arylated pyrroles in moderate to good yields under the standard conditions with good substrate tolerance. Interestingly, while N-benzoyl pyrroles reacted well, the use of substrates with a thiophene or furan ring indicated that the thiophene and furan rings are more reactive than pyrrole for the present catalytic system.