Sulfur–silicon bond activation catalysed by Cl/Br ions: waste-free synthesis of unsymmetrical thioethers by replacing fluoride catalysis and fluorinated substrates in SNAr reactions

Abstract

In contrast to conventional activation of Nu–SiR₃ reagents by F ion attributed to the strong affinity of Si to F, S–Si activation can now be achieved using Cl/Br ions of TBAX as catalysts via formation of weaker X–Si bonds and Me₃Si–X. This led to a waste-free synthesis of unsymmetrical thioethers via F-free S_NAr reactions of activated (hetero)aryl halides and RS–SiMe₃, with recovery of the useful Me₃Si–X reagent in high yields.