AbstractAn unexpected domino reaction of electron‐deficient 2,4‐dienes with 2‐halo‐1,3‐dicarbonyl compounds, employing the readily available N‐(4‐trifluoromethylbenzyl)cinchonium bromide as the phase‐transfer catalyst, provides an access to functionalized cyclopentenes and fulvene derivatives with excellent regio‐, chemo‐ and stereoselectivities. A plausible mechanism for this unprecedented domino reaction is given.magnified image