Generation of Fluoro(thio)carbenes from Me3SiCF2SAr

Generation of carbenes bearing a fluorine atom and an arylthio group from the difluorinated silicon reagents is described. The carbene generation is performed using a combination of lithium methoxide and lithium chloride, which behave as Lewis basic and Lewis acidic activators, respectively. The reactivity of fluoro(thio)carbenes was evaluated by trapping with an alkene and an aminoborane. Quantum chemical calculations allowed comparison of the fluoro(thio)carbene with difluorocarbene.