Potassium Carbonate Participates In The Reaction Of Nitrogen-oxygen Bond Cleavage Rearrangement Of Pyridinium To Synthesize Pyridylphenol

Rearrangement reactions are very useful for the preparation of synthetically challenging compounds from readily accessible precursors.What is more,rearrangement reactions are also one of the most important ways to form new C-C or C-heteroatom bonds.This kind of reaction have been widely used in the synthesis of fine chemicals,drugs and pesticides.Except from the C-C bond cleavage assisted rearrangement reactions,such as Claisen reaction,N-O bond cleavage assisted rearrangement reactions are also significant for the synthesis of heterocyclic compounds such as polysubstituted furfuran,pyridine or pyrrole.However,compared with C-C bond assisted rearrangements,N-Obond assisted· rearrangement reactions are largely undeveloped and are often suffer from disadvantages including hardh reaction conditions,bed functional group tolerance,low yields and selectivity.Additionally,these reactions are often employing transition metal or toxic solvent,which have bed influence for economy and environment.Thus,the development of novel protocol of N-O bond assisted rearraangement reactions remains highly desirable.In this article,the author elaborate N-O bond cleavage assisted rearrangement and related reactions.Moreover,based on our interest in the transformations of oxime and the purpose of develping novel,simple and environmentally friendly rearrangement reaction,we herein report a cyclization and[1,3]rearrangement reaction of y,8-alkynyl oximes for the synthesis of pyridols.The process accomplishes an efficient[1,3]rearrangement of O-vinyl oxime intermediate which is in situ generated from the intramolecular nucleophilic addition of γ,δ-alkynyl oximes.The reaction proceeded under mild conditions in the absence of any transition metal catalyst,oxidant or strong base.The reaction employs readily accessible starting materials,tolerates a wide range of functional groups,and gives a variety of synthetically challenging pyridols in good yields.The employment of glycerol as a solvent makes the reaction economical,nontoxic and environmental.