In contrast to conventional activation of NuâSiR3 reagents by F ion attributed to the strong affinity of Si to F, SâSi activation can now be achieved using Cl/Br ions of TBAX as catalysts via formation of weaker XâSi bonds and Me3SiâX. This led to a waste-free synthesis of unsymmetrical thioethers via F-free SNAr reactions of activated (hetero)aryl halides and RSâSiMe3, with recovery of the useful Me3SiâX reagent in high yields.
与传统通过
氟离子激活Nu–SiR3试剂(归因于
硅对
氟的强亲和力)相比,S–Si激活现在可以通过T
BAX的
氯/
溴离子作为
催化剂实现,这通过形成较弱的X–Si键和Me3Si–X。这样可以实现无废物合成不对称的
硫醚,通过活化的(杂)芳基卤化物和RS–SiMe3进行无
氟的SNAr反应,并高产率回收有用的Me3Si–X试剂。