Aryne-mediated fluorination: Synthesis of fluorinated biaryls via a sequential desilylation-halide elimination-fluoride addition process
Résumé
An unusual aryne-mediated fluorination of arom. ring systems during the desilylation of ortho-bromo-biphenyl-trimethylsilanes with tetrabutylammonium fluoride (TBAF) is described. In situ formation of an aryne and addn. of fluoride affords fluorinated biphenyls. The structures have been confirmed by synthesis of authentic samples via Suzuki-Miyaura cross-coupling and X-ray anal. In situ trapping expts. with furan proved the transient formation of aryne by fluoride-induced displacement of the TMS group and subsequent bromide elimination.