Transition metal control in the reaction of alkyne-substituted phenyl iodides with terminal alkynes: Sonogashira coupling vs cyclic carbopalladation
作者:Filip Teplý、Irena G. Stará、Ivo Starý、Adrian Kollárovič、David Šaman、Pavel Fiedler
DOI:10.1016/s0040-4020(02)01154-7
日期:2002.10
Reaction between terminal alkynes and phenyl iodides bearing a tethered alkyne unit can be effectively controlled by the nature of a transition metal catalyst. Whereas the use of Pd(0)/Cu(I) promotes the expected Sonogashira coupling to give phenyl alkynes, the absence of the copper co-catalyst triggers a palladium-mediated cyclisation providing 1,2-dihydroacenaphthylene, 1H,3H-benzo[de]isochromene
通过过渡金属催化剂的性质可以有效地控制末端炔烃和带有链式炔烃单元的苯基碘化物之间的反应。而使用的Pd(0)的/铜(I)促进预期Sonogashira偶联,得到苯基炔烃,不存在铜助催化剂触发器钯-介导的环化,提供1,2- dihydroacenaphthylene,1 ħ,3 ħ -苯并[ de ]异戊烯,(1 Z)-1-(2-亚丙基)-2,3-二氢-1 H-茚和(4 E)-4-(2-亚丙基)-3,4-二氢-1 H-异戊二烯衍生物。在后一种Pd催化的双组分方法中,产物分布取决于炔烃取代的苯基碘化物,末端炔烃和用作溶剂的仲胺的结构。拟议的反应机制反映了中间σ-(乙炔)与π-炔烃Pd(II)配合物的竞争性形成。