Br?nsted Acid-catalyzed Intramolecular Cyclization Of In Situ Formed Allylic Iminum Ions

Two novel Br?nsted acid-catalyzed intramolecular cyclization reactions of in situ formed allylic iminum ions were developed in this paper.The thesis is divided into three part:Part?:(1)This part summarizes the process of Br?nsted acid catalysts in catalytic reaction;(2)It summarizes the development prospects of Br?nsted acid catalysts;(3)It summarizes the application of iminum ions intermediates in cyclization reaction.Part? : This prat deals with the study of Br?nsted acid-catalyzed intramolecular cyclization of in situ formed allylic iminum ions for the construction of cyclopentyl [b] indole skeleton.The cyclopentyl [b] indole skeleton is widely found in natural products and drug molecules,and many of them have anti-tumor,anti-bacterial,insecticidal and other effects,thus,the development of efficient methods for construction of cyclopentyl [b] indole skeleton is of great importance.In this thesis,indole derivatives are constructed from trifluoroacetic acid catalyzed intramolecular cyclization reaction of indole-substituted allyl iminum ions.However,to date,the related studies are rather rarely reported.In the reaction process,due to the hygroscopicity and the corrosivity of TFA,we use silica supported TFA as catalyst.Because water is only by-products.This method not only enriches the application of Br?nsted acid catalyst in catalytic synthesis,but also provides the basis for the synthesis of indole derivatives.Part?: A Polyphosphoric acid(PPA)catalyzed intramolecular cyclization of in situ formed allylic iminum ions for the construction of indene derivatives was developed.The indene ring skeleton is the core backbone of many natural products,which exist widely in biologically active molecules,functional materials and transition metal complex.Particularly metal-indenyl complexes have remarkable effects on catalyzing olefin polymerization.Therefore synthetizing indene derivatives is of great significance.PPA is a strong inorganic acid and has strong dehydration performance,which is used widely in intramolecular and intermolecular acylation,heterocyclic synthesis and acid catalyzed reaction.This subject provides a unique and novel method for constructing indene ring skeleton by use of PPA exo-model in the catalysis of the allyl imine ion intermediate.The reaction has the following major advantages:(1)low-cost raw materials.(2)The substrate has good general application(It is not only suitable for the rich electronic system,but also for electron deficient aldehyde).(3)This reaction has high atom economy.This topic provides a better research basis for the synthesis of indane derivatives.