Silyldefluorination of Fluoroarenes by Concerted Nucleophilic Aromatic Substitution

The reaction of readily generated silyl lithium reagents with various aryl fluorides to provide the corresponding aryl silanes is reported. DFT calculations reveal that the nucleophilic aromatic substitution of the fluoride anion by the silyl lithium reagent proceeds through concerted ipso substitution. In contrast to the classical nucleophilic aromatic substitution, this concerted ionic silyldefluorination also occurs on more electron‐rich aryl fluorides. Just one step! Reactions of readily generated silyl lithium compounds with fluoroarenes provide the corresponding aryl silanes under very mild conditions. DFT calculations show that these transformations proceed through concerted nucleophilic aromatic substitution.