Studies On MCR Of Alkynes For Tandem Radical And Nucleophilic Cyclization Reactions

This thesis mainly describes the reactions by using alkynes as substrates,which react with fluorine radicals to generate the new vinyl radical intermediates in the presence of transition metal palladium and base.Subsequent recombination with other organic functional groups generates a variety of substituted olefin products,and alkynes difunctionalization reactions are successfully achieved.Alkynes difunctionalization is a significant process for preparing tri-and tetra-substituted olefin derivatives.The olefins can be constructed with high regioselectivity and stereoselectivity under the catalysis of transition metals.Compared with olefin-related reactions to build functionalized olefins,the raw materials of alkynes difunctionalization reactions are simpler and easier to obtain.Meanwhile the diversity of functional groups makes the products more abundant.In addition,the one-pot multi-component reactions can shorten the reaction time,simplify the reaction process,and it do not require the separation of intermediate species,which greatly improve the reaction efficiency and economical and environmentally friendly.The first chapter of thesis briefly introduces the research progress of the difluoro/perfluoroalkylation difunctionalization reaction of alkynes.The thesis shows us the development history of alkyne fluoroalkylation difunctionalization reaction in the past 70 years,and highlights the significant progress had made in this field.A series of functional groups and various fluorine radicals are introduced directly into alkynes through the alkyne difunctionalization reaction,such as reactions of alkynes hydrofluoroalkylation,halofluoroalkylation,borylation-fluoroalkylation,arylationfluoroalkylation,alkynylation-fluoroalkylation,trifluoromethylthiolation-fluoroalkylation,sulfamidation-fluoroalkylation,cyanofluoroalkylation,phosphorylation-fluoroalkylation,cyclization-fluoroalkylatio.The second chapter focuses on the system work of alkyne difunctionalization fluoroalkylation reactions during my research time.Ethyl iododifluoroacetate or iodoperfluoroalkane produces fluorine radicals in the presence of transition metal palladium and base.The stereoselective and regioselective addition of alkynes with fluorine radicals occurs,which gives the vinyl radical intermediate.We strive to insert carbon monoxide into the molecules under mild conditions,such as room temperature and normal pressure,to construct ?,?-unsaturated carbonyl compounds.These reactions show us the universality and superiority of the carbonylation process involving alkynes and fluorine radicals for the preparation of fluoroalkyl-substituted ?,?-unsaturated carbonyl compounds.In some reaction cases,some fluorine-containing polymer materials have been prepared,which display many excellent physical properties on the same sample.Its application potential became more apparent in the aerospace and marine fieldsDuring the work of fluoroalkylation reactions through alkyne difunctionalization,we unexpectedly discovered that imidazole derivatives can be conveniently prepared on a large scale in a short time at room temperature when alkynes,nitriles,and potassium tert-butoxide meet,which happens even in the absence of metal and solvent.it means that the reactions can occur while the substrates just put together.Atomic utilization of the reaction is extremely high,and it's environmentally friendly.In Chapter 3,it focuses on describing the superior performance of the nucleophilic domino cyclization multi-component reaction to prepare complex imidazoles compounds from simple raw materials under the simple reaction conditions.This is also the development trend of green chemistry in the future.