Efficient Access to 3, 4‐Diarylpyrroles through Selective Bromination and Subsequent Suzuki‐Coupling Reaction

Abstract An efficient and practical synthesis of 3, 4‐disubstituted pyrrole was developed through bromination and the subsequent Suzuki‐coupling reaction. The bromination of pyrrole‐1‐dimethylsulfonamide occurred selectively on the two β‐positions to afford 3, 4‐dibromo‐ N , N ‐dimethyl‐1 H ‐pyrrole‐1‐sulfonamide, from which symmetrical and unsymmetrical 3, 4‐diarylpyrroles were prepared through a stepwise Suzuki‐coupling reaction. This reaction is complementary to the existing methods and is well‐tolerable by a variety of functional groups. The bromination can readily be scaled‐up to gram‐scale synthesis without decreasing the yield. In addition, the other halogenations of pyrrole were also studied, and different chloroproducts were isolated.