ChemInform Abstract: Palladium‐Catalyzed Direct Desulfitative Arylation of Pyrroles Using Benzenesulfonyl Chlorides as Alternative Coupling Partners.

The reactivity of pyrrole derivatives for palladium‐catalysed desulfitative arylation has been investigated. 1‐Methyl‐, 1‐phenyl‐ and 1‐benzylpyrroles were successfully coupled with a variety of benzenesulfonyl chlorides using a phosphine‐free catalyst. Highly regioselective arylations at carbon C2 of pyrroles were observed in all cases. A wide variety of substituents on the benzenesulfonyl derivative was tolerated. It should be noted that even bromo‐ and iodo‐benzenesulfonyl chlorides were successfully coupled with pyrrole derivatives without cleavage of the CBr or CI bonds, allowing further transformations. Surprisingly, with indoles, mixtures of C2‐ and C3‐arylation products were obtained. magnified image