C-H Bond Participate In Ring-opening/Cyclization Of Three-membered Carbocylic Compounds

Three-membered carbocyclic compounds is one of the crucial skeletons in organic chemistry,which widely exists in biologically molecules and natural products.It is also an important raw material for the synthesis of pharmaceutical and new materials.Three-membered carbocyclic compounds is the smallest cyclic compound with highly strained,which can easily undergo ring-opening/cyclization in the presence of transition metals and Lewis acids.C-H bonds are the most basic chemical bonds in organic chemistry,and their conversion can provide broad pathway for the synthesis of organic compounds.Moerover,only one hydrogen atom is wasted in the C-H bond functionalization.Therefore,this reaction is an important research field with high atom economical in organic chemistry.The ring-opening/cyclization of three-membered carbocyclic compounds is a kind of reaction in which the cleavage of C-C bond,then undergoes cyclization to afford five-or six-membered cyclic compound.Transition metals,Lewis acids and strong oxidants are inevitably used in the ring-opening/cyclization of three-membered carbocyclic compounds.In recent years,ring-opening/cyclization of three-membered carbocyclic compounds became a hot topic in organic chemistry and achieved fanscinating results.In order to expand the types of ring-opening/cyclization three-membered carbocyclic compounds,we have developed several simple,efficient,and convenient methods for the ring-opening/cyclization of three-membered carbocyclic compounds.Therefore,this thesis mainly disscusses the ring-opening/cyclization three-membered carbocyclic compounds with C-H bonds.The main contents are as follow:?1?The first chapter is a literature review.The research progress of ring-opening/cyclization reaction of three-membered carbocyclic compounds in recent years is mainly elaborated.The main contents include?I?ring-opening/cyclization reaction of methylenecyclopropanes?MCPs?;?II?ring-opening/cyclization reaction of vinylcyclopropane;?III?ring-opening/cyclization reaction of cyclopropanol.?2?A mild and efficient ring-opening/cyclization of MCPs with C?sp³?-H bond of ethers is eatablished.The ring-opening/cyclization of MCPs,which do not need any transition metals,can give a series of 3,4-dihydronaphthalenes in moderate to good yilds.In this reaction,the transformation of simple ethers to highly functionalized ethers is achieved under the mild conditions.?3?A silver-mediated ring-opening/cycalizaion of MCPs with C?sp³?-H bond of alpha alkyl ketones is described.Ag SO₄ is used as catalysts in this one-pot reaction,which realizes the C-C?-bond acemethylation/arylation.It provides a novel and efficient method for the acemethylation/arylation by one-pot cleavage of one C-C bond and construction of two new C-C bonds.?4?A Lewis acid-catalyzed ring-opening/cycalizaion of MCPs with C?sp²?-H bond of aldehydes is presented under simple conditions.This reaction has excellent functional group tolerance and broad substitute scope.In this reaction,the acylation/arylation of MCPs is achieved via a radical pathway and allows the cleavage of one C-C bond and construction of two new C-C bond.