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

Abstract

We have discovered that three molecules of arylacetylene are rapidly (15 min) assembled with one molecule of nitrile at room temperature in the KOBu^t/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 CN, then to the CC and CC bonds of the intermediates, followed by pyrrole ring closure via the intramolecular nucleophilic addition of the NH functional group to the CC bond of the final intermediates.