Efficient Reagents for Non-Cryogenic Br-Li Exchange in Bromopyridines

Significance

The regioselective functionalization of the pyridine ring is an important synthetic problem, considering the wide appearance of this heterocycle in the structures of biologically active compounds and ligands. The authors developed an efficient method for the highly selective bromine-lithium exchange in the α-position of the ring, also in the presence of the usually more reactive β-bromo substituent. The reaction does not require low temperatures and thus can be readily performed on an industrial scale.