Ligand-Enabled, Iridium-Catalyzed ortho-Borylation of Fluoroarenes

A terpyridine derivative and an iridium complex catalyze the C-H borylation of a stoichiometric amount of a fluoroarene with high ortho-selectivity and tolerance of functional groups such as bromide, chloride, ester, ketone, amine, and in situ-borylated hydroxyl. Complex drug molecules such as haloperidol can be selectively borylated ortho to the F atom. The terpyridine ligand undergoes rollover cyclometalation to produce an N,N,C-coordinated iridium complex, which may either selectively borylate the fluoroarene by itself or undergo reductive elimination to produce a borylated ligand.

Automated summary

A terpyridine derivative and an iridium complex have been found to catalyze the C-H borylation of fluoroarenes with high ortho-selectivity and tolerance of various functional groups. This discovery could have important implications for the synthesis of complex drug molecules.