Three-component reaction of Δ 1 -pyrrolines, electron-deficient acetylenes, and NH-pyrroles. Synthesis of 2-(pyrrolyl)pyrrolidinyl acrylonitriles and enones

Addition of NH-pyrroles acting as electrophiles to zwitterionic adducts of Δ 1 -pyrrolines and electron-deficient acetylenes (20–25 °C, 4–30 h) gave 2-(pyrrol-1-yl)pyrrolidin-1-ylacrylonitriles and 2-(pyrrol-1-yl)pyrrolidin-1-ylenones in 18–48% yields.