Tandem Ring-Contraction/Regioselective C–H Iodination Reaction of Pyridinium Salts
Juan Tang, Chaoqun Zhao, Shun Li, Jing Zhang, Xueli Zheng, Maolin Yuan, Haiyan Fu, Ruixiang Li, Hua Chen
Abstract
A facile route for direct access to the 4-iodopyrrole-2-carbaldehydes from pyridinium salts has been successfully developed, which undergoes cascade pyrrole-2-carbaldehydes construction/selective C4 position iodination process. Using Na 2 S 2 O 8 as an oxidant and readily available sodium iodide as an iodine source, a variety of 4-iodopyrrole-2-carbaldehydes were obtained in good to excellent yields. Atom- and step-economy, good functional group tolerance, high regioselectivity, as well as mild conditions entail this transformation an alternative strategy for enriching pyrroles library.
Topics & Concepts
RegioselectivityHalogenationChemistryTandemPyridiniumIodineIodideRing (chemistry)Combinatorial chemistrySodium iodideAtom economyCascade reactionMedicinal chemistryOrganic chemistryCatalysisMaterials scienceComposite materialCatalytic C–H Functionalization MethodsSynthesis and Characterization of PyrrolesOxidative Organic Chemistry Reactions