Metallation of Aryl Bromides Bearing a Potassium Trifluoroborate Moiety

Significance

Potassium aryltrifluoroborates present in many cases a convenient alternative to usual arylboronic acids in Suzuki cross-coupling and other transition-metal-catalyzed reactions. However, the value of high reactivity of these reagents was so far diminished by the lack of methods for their direct functionalization that this is the first report of the functional-group manipulation in the presence of an anionic trifluoroborate moiety in the molecule. Br-Li exchange, followed by addition of an electrophile, affords a number of interesting compounds bearing a synthetically very useful aryltrifluoroborate group.