The Structural Proliferation of 2,6-Difluoropyridine through Organometallic Intermediates

Contrary to a literature claim, 2,6‐difluoropyridine‐3‐carboxaldehyde can be readily prepared by consecutive treatment of 2,6‐difluoropyridine with lithium diisopropylamide and N,N‐dimethylformamide. Regioselective displacements of fluorine from the aldehyde by nucleophiles were carried out. To demonstrate the versatility of the organometallic approach, some two dozens of further 2,6‐difluoropyridine derivatives were prepared applying a combination of modern organometallic methods such as site selective hydrogen/metal and halogen/metal permutations and deprotonation‐triggered heavy halogen migrations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)