Topochemical mechanoactivated phosphonylethynylation of pyrroles with chloroethynylphosphonates on solid Al2O3 or K2CO3 media

Dialkyl 2-(1H-pyrrol-2-yl)ethynylphosphonates have been synthesized from their respective pyrroles by a transition metal-free, topochemical mechanoactivated phosphonylethynylation (room temperature, 24-48 h) using chloroethynylphosphonates on solid Al2O3 (40-58% yield) or K2CO3 (38-43% yield).