Synthesis of N,O-Bidentate Difluoroboron Complexes via Iodide-Promoted Demethylative Borylation

N,O-Bidentate difluoroboron complexes were synthesized from (2-methoxyaryl)pyridines by iodide-promoted demethylative borylation. In the presence of Bu4NI and Et3N, (2-methoxylaryl)pyridines smoothly reacted with BF3·OEt2 to afford the N,O-bidentate difluoroboron complexes. The amounts of BF3·OEt2, Bu4NI, and Et3N strongly influenced the reaction efficiency. The optimal conditions were determined through Bayesian optimization, and several N,O-bidentate difluoroboron complexes were obtained efficiently under the reaction conditions. The resulting complexes exhibited fluorescent properties with large Stokes shifts, which were in good agreement with the calculated properties.