Stereoselective synthesis of CF3-substituted trans- and cis-enediynes via carbocupration or hydrostannation reactions of CF3-containing diyne

CF₃-containing diyne, readily prepared from (Z)-2,3,3,3-tetrafluoro-1-iodoprop-1-ene in two steps, was smoothly subjected to carbocupration reaction with various organocuprates, followed by treatment of the resultant carbocupration adducts with iodine, the corresponding vinyl iodides being formed in good yields in a cis-addition manner. Thus obtained iodide could be successfully converted into CF₃-substituted trans-enediynes in high yields. Also, hydrostannation reaction of the diyne proceeded well in a trans-addition manner to give the corresponding vinylstannane in high yield. The vinylstannane was also found to be effectively convertible to CF₃-substituted cis-enediynes in high yields.