REACTION DE LA BROMO-3 PYRIDINE AVEC LE DIISOPROPYLAMIDURE DE LITHIUM. MECANISMES DE METALLATION ET DE MIGRATION D'HALOGENE. REGIOSELECTIVITE DE L'ADDITION POLAIRE SUR LA PYRIDYNE-3,4

Article abstract of DOI:10.1016/0040-4020(82)80190-7

3-bromo pyridine behaviour towards lithium diisopropyl amide (LDA) in THF is studied.A careful study of the experimental conditions point to a metallation reaction in a position 4 and a "halogen dance" mechanism with isomerisation into a 4-bromo pyridine.Conversion into diisopropylamino compounds occurs simultaneously with a 3 oriented elimination-addition (EA) reaction from transient isomeric lithio-derivatives and a competing addition-elimination (AE) mechanism from the in situ formed 4-bromo pyridine.