Iron-Catalyzed One-Pot\nCascade Reactions of Oximes\nwith Inactivated Saturated Ketones: Entry to Highly Substituted Pyridines

An iron-catalyzed oxidative [3 + 3] annulation of oxime\nesters\nwith inactivated saturated ketones is described. This cascade strategy\nallows one-step rapid synthesis of various structurally important\npyridines through an oxidative dehydrogenation/annulation/oxidative\naromatization sequence via direct α,β-dehydrogenation\nof simple saturated ketones followed by annulation with oximes. This\nmethod shows good functional group tolerance, readily accessible starting\nmaterials, a wide substrate scope, high chemoselectivity, and no need\nfor extra stoichiometric oxidant and is also applicable to the late-stage\nfunctionalization of natural products.