已经开发出一种有效的直接合成吡唑并[5,1- a ]异吲哚的方法,该方法利用钯催化的1-(2-卤代苄基)吡唑的分子内CH键活化作用。发现在这些反应中必须使用氯化锂(LiCl),以抑制当C-3未取代时在吡唑并[5,1- a ]异吲哚的C-3位置的进一步CH键活化。该方案可用于通过顺序的分子内和分子间CH键活化合成具有六元中心环系统的吡唑并[5,1- a ]异喹啉和完全取代的吡唑并[5,1- a ]异吲哚。
Phosphine-Catalyzed [3+2] Cycloaddition Reactions of Azomethine Imines with Electron-Deficient Alkenes: A Facile Access to Dinitrogen-Fused Heterocycles
for the phosphine‐catalyzed [3+2] cycloadditionreaction of azomethineimines with diphenylsulfonyl alkenes to give dinitrogen‐fused bi‐ or tricyclic heterocyclic compounds in high yields has been described. Moreover, two phenylsulfonyl groups installed on the heterocyclic products could be conveniently removed or transformed to other functional groups, making the reaction more useful.