Synthesis of TetrasubstitutedPyrroles via DBU-MediatedCyclization of Unactivated Propargyl Tertiary Amines

Compared with the well-developed cyclization of functionalized propargylamines, the use of unactivated tertiary propargylamines to access pyrroles remains challenging. Herein, we report an efficient method for constructing tetrasubstituted pyrroles via a DBU-mediated intramolecular cycloaddition of <i>N</i>-alkyl propargylamines. This reaction employs cyclization to access dihydropyrrole intermediates, followed by oxidation to produce pyrroles in the presence of 2,3-dichloro-5,6-dicyano-<i>p</i>-benzoquinone. In addition, a broad substrate scope, high atom economy, high selectivity, and simple operation are also advantages of this protocol.