Rapid, room-temperature self-organization of polyarylated 1H-pyrroles from acetylenes and nitriles in the KOBut/DMSO system

We have discovered that three molecules of arylacetylene are rapidly (15 min) assembled with one molecule of nitrile at room temperature in the KOBut/DMSO system to afford 2-aryl-3-arylethynyl-4-aryl-5-benzyl-1H-pyrroles in up to 76% yield. We assume that this unprecedented self-organization process involves the cascade addition of acetylenic carbanions, first to the CN, then to the CC and CC bonds of the intermediates, followed by pyrrole ring closure via the intramolecular nucleophilic addition of the NH functional group to the CC bond of the final intermediates.