Catalytic Synthesis of Potassium Acyltrifluoroborates (KATs) through Chemoselective Cross-Coupling with a Bifunctional Reagent

Potassium acyltrifluoroborates (KATs) are increasingly important functional groups, and general methods for their preparation are of great current interest. We report a bifunctional iminium reagent bearing both a tin nucleophile and a trifluoroborate, which was applied in chemoselective Pd-0-catalyzed Migita-Kosugi-Stille cross-coupling reactions owith aryl and vinyl halides. This method gives access to previously inaccessible aromatic and alpha,beta-unsaturated acyltrifluoroborates, including precursors to amino-acid derived KATs.