Zirconocene-promoted coupling reaction of terminal acetylenes to geminal enediynes in the presence of p-chloranil

Reaction of alkynyllithium with zirconocene dichloride in the presence of quinones afforded zirconoenediynes in good yields. Treatment of the zirconoenediyne with p-chloranil in the presence of CuCl afforded 1,1,4,4-tetraethynyl-1,3-diene in good yield. In the presence of CuCl and/or Pd(PPh3)4, the zirconoenediynes could be transformed into various enediyne derivatives through coupling reaction with electrophiles.