Condensation of Alkynes with Cyclopentadiene via Titanacyclopentadiene Complexes

二氯化二茂钛与两个等量炔反应生成双（环戊二烯基）钛环戊二烯配合物，产率高。随后，偶氮苯以“一锅”方式加成，形成了高收率的独立衍生物。不同的炔烃可与环戊二烯基配体进行偶联反应。当采用苯或聚芳烃桥接二炔时，相应的环戊二烯融合二烯收率较高。这些独立产物分别用BuLi和zrcl4进行处理，得到了产率较高的二（独立基）氯化锆二茂烯衍生物。

Titanocene dichloride reacted with two equiv of alkynes to form bis(cyclopentadienyl)titanacyclopentadiene complexes in excellent yields. Subsequently, addition of azobenzene, in ‘one-pot’ manner, led to the formation of indene derivatives inhigh yields. Various alkynes were applicable for the coupling reaction withcyclopentadienyl ligand. When benzene or polyarene bridged diynes were employed, thecorresponding cyclopentadiene-fused acenes were obtained in good yields. These indeneproducts were treated with BuLi and ZrCl4successively to give bis(indenyl)zirconocenedichloride derivatives in good yields.