Chemoselective reduction of 2-acyl-N-sulfonylpyrroles: synthesis of 3-pyrrolines and 2-alkylpyrroles.

The partial reduction of pyrroles is not a common practice even though it offers a potential route to pyrroline building blocks, commonly used for synthesis. We have investigated the reduction of 2-acyl-N-sulfonylpyrroles and by varying the hydride source and solvent, achieved a chemoselective reduction, leading to 3-pyrrolines and alkyl pyrroles in high yield.