Palladium-catalyzed intermolecular [3 + 2] carbocyclization of alkynols and propiolates: an efficient entry to halo-cyclopentadienes

A novel and efficient Pd-catalyzed intermolecular [3 + 2] carbocyclization of alkynols and electron-deficient alkynes for the synthesis of halo-cyclopentadienes (Cps) has been developed. The present protocol employs simple propargyl alcohols as the C3 group to participate in the cyclization reaction, providing a highly convenient and atom-economical entry to the halo-cyclopentadiene framework.