Stereoselective preparation of alkenyl sulfide was carried out via syn-hydrozirconation of the alkynyl sulfide. Regiochemistry of halogenation of the thioalkenyl zirconocene could be switched by different halides. α-Chloroalkenyl sulfide or β-haloalkenyl sulfide (Br, I) could be obtained by the treatment of NCS or NBS (NIS), respectively. Possible mechanism of halogenation of the thioalkenyl zirconocene was set up herein.

α-Methylenyl zirconacyclopentenes are synthesized regio- and stereoselectively via reductive intermolecular cross-coupling of alkynes and allenes promoted by zirconocene species ‘Cp2Zr’. An interesting reductive intramolecular coupling of the α-methylenyl zirconacyclopentene has been observed in the presence of DMAD/CuCl, resulting in the generation of cyclobutene with an exocyclic double bond. Polysubstituted 1,4-dienes can be given with high selectivity and good yields.Synthesis and application of α-methylenyl zirconacyclopentene.