Coupled Lewis Base and Phase-Transfer Catalysis for Imine Trifluoromethylation

Significance

Bernardi and colleagues developed a useful protocol for the addition of trifluoromethylsilane (2) and other silicon nucleophiles to various imines 1 using a combination of Lewis base and solid-liquid phase-transfer catalysis. The quaternary ammonium precatalyst salt 3 was used as the Lewis base to activate the silane reagent, while a stoichiometric amount of insoluble sodium phenoxide served to regenerate the catalyst after every turnover. An array of previously unsolved or challenging substrates was successfully transformed. In addition, encouraging initial results were observed in the asymmetric version of the reaction using a cinchona derivative 4.