Oxidative Radical Reactions Of Unsaturated Hydrocarbons With Silanes And Annulations Of Triazole With Alkynes

Silicon is very common,and it's content in the earth's crust is second only to oxygen.Organosilicon compounds have unique chemical,physical,and bioactive properties which grant them wide applications in organic chemistry,materials science,agrochemistry,and medicinal chemistry.For a long time,chemists have devoted themselves to the development of silicon chemistry.A large num ber of studies and reports have been made toward efficient methods for the synthesis of organic silicon compounds.In particular,transition metal catalyzed the coupling reaction with silylation agents has become one of the most common methods for synthesizing organic silicon compounds,however,the use of toxic or precious transition metals makes the environment unfriendly,and leads to high reaction costs.In recent years,the method that synthesize organosilicon compounds by free-radical reaction of silanes and unsaturated hydrocarbons has been developed rapidly and has gradually emerged as a research hotspot in the field of organic synthesis.Nitrogen-containing heterocyclic compounds are the basic structural skeletons of many natural products and drugs.Their synthesis has broad application prospects in the research and development of natural products and drug molecules,and therefore has been highly concerned by chemists.In recent years,1-sulfonyl-1,2,3-triazoles are capable of forming a highly active?-imine metal carbene under the action of a transition metal catalysts,especially a rhodium catalyst,thus are very versatile synthons for constructing nitrogen-heterocyclic compounds.This dissertation focuses on the oxidative radical reaction of unsaturated hydrocarbons with silanes and the annulation of 1-sulfonyl-1,2,3-triazoles with alkynes for the synthesis of various organosilicon compounds and nitrogen-containing heterocyclic compounds.This dissertation includes five parts:In chapter 1,recent advance in the free-radical reaction of silanes with unsaturatedhydrocarbonsandrhodium-catalyzedannulationof1-sulfonyl-1,2,3-triazole was summarized.The free-radical reactions of silanes and unsaturated hydrocarbons include silylation reaction and difunctionalization reaction.Methods for synthesis of nitrogen-containing heterocyclic compounds from triazoles via including rhodium-catalyzed Intermolecular and intramolecular cyclization were also discussed.In chapter 2,an iron-catalyzed intermolecular 1,2-difunctionalization of alkenes with silanes and nucleophiles using an oxidative radical strategy was described.Employing silanes allows divergent alkene 1,2-difunctionalizations,including1,2-aminosilylation,1,2-arylsilylation,and 1,2-alkylsilylation,which rely on a wide range of nucleophiles,namely,amines,amides,indoles,pyrroles,and 1,3-dicarbonyl compounds,thus providing a powerful platform for producing diverse silicon-containing alkanes.In chapter 3,a copper-catalyzed oxidative annulation cascades of 1,7-enyne and silane was introduced.The reaction enables selectively synthesis of different silicon-containing heterocyclic compounds relying on types of silanes,while using tertiary silanes,selective functionalization of Si-H/silyl C(sp~3)-H bonds provided six-member silicon-containing heterocyclic compounds,when using secondary silanes and HSi(TMS)3,dual Si-H bonds or Si-H/Si-Si bonds were selectively cleaved leading to five-member silicon-containing heterocyclic compounds.This method provides an efficient route for the synthesis of complex silicon-containing heterocyclic compounds.In chapter 4,a novel rhodium(?)-catalyzed[3+2]/[5+2]annulation of4-aryl-1-tosyl-1,2,3-triazoles with internal alkynes was presented.The cyclization of aryltriazole with two molecular alkynes,which was carried out using[Cp*RhCl2]2 and AgSbF6 as catalysts,Cu(OAc)2 as oxidant and DCE as solvent at 85 ~oC,achieved dual C(sp~2)-H bonds functionalization.This reaction selectively synthesized two types of indeno[1,7-cd]azepines by changing the alkyne type.When diaryl alkynes were used,indeno-[1,7-cd]azepin-1-ols were obtained,and 1-methyleneindeno[1,7-cd]azepines were produced using arylalkyl alkynes.Inchapter5,asilver-catalyzedcyclizationof N-sulfonyl-4-(2-(ethynyl)aryl)-1,2,3-triazoles was investigated and discussed.Initially,opening of the triazole ring by the Dimroth rearrangement and then extrusion of nitrogen gas afforded the silver carbenoid intermediate when silver hexafluoroantimonate was used under heating.Subsequently,isoquinoline derivatives were obtained through a two intramolecular cyclizations and one ring opening process.This method provids an efficient route for the construction of isoquinoline derivatives.