Studies On Radical Oxidative Cycloaddition Reaction And The Synthesis Of Azaborines

This thesis aims at the studies on various types of radical oxidative cycloaddition to construct novel functional molecules.Also,the synthesis of Azaborines is reported.It mainly consists of the following five chapters.Chapter ?:In part 1,we simply summarized four types of unilateral cyclization reaction,including ionic cyclization,radical cyclization,pericyclic reaction and transition-metal catalyzed cyclization reaction.The former three reaction types follow the Baldwin Cyclization Rules.At the same time,we also summarized the advantages of the free radical cyclization process,and put forward outlook on the importance of free radical cyclization accompanied with aryl addition to synthesize small molecule cyclic compounds.In part 2,we systematic summarized the different methods to construct oxindoles,including transition-metal catalyzed olefin insertion,C-H activation,as well as the radical oxidation cycloaddition.According to different radical forms,the radical oxidation cycloaddition to build oxindoles is divided into the following four categories: sp3-carbon radicals,sp2-carbon radicals,trifluoromethyl radical and heteroatom radicals like halogen,and reaction examples were made in detail respectively.Finally,we introduced the rhodium-catalyzed C-H activation of ?-position of alcoholic hydroxyl,and analyzed its mechanism.In part 3,we introduced two kinds of enyne cyclization reactions including transition-metal catalyzed process and free radical addition.Au,Rh,Pd are illustrated in detail to show the law of transition-metal catalyzed reaction.At the same time,we introduced the migration process during rearrangement reaction along with free radical addition.According to the different position of migration point,we classified the rearrangement reaction into four categories,namely: 1,2-migration,1,3-migration,1,4-migration and 1,5-migration.Finally,we summarized the reaction between transition metals and phosphorus compounds,including phosphorus oxides directed C-H activation reaction and reactions to build C-P bonds.Meanwhile,we also focused on the way to phosphoryl radical initiation and the influence factors during nucleophilic addition process.Chapter ?:In chapter 2,we have developed the reaction to synthesize hydroxyl-substituted oxoindoles under metal-free conditions.After the addition of carbon radical at ?-position of alcohol to activated alkene followed by addition on aromatic ring,the intermediate translated to oxindoles by dehydrogenation.Through the kinetic isotope effect experiment,we identified that the C-H bond cleavage on the ortho-aromatic ring was the rate-determined step.Chapter ?:In chapter 3,we have discovered the way to P-containing fluorene derivatives through the cascaded radical addition and oxidative cyclization by employing phosphorus oxides and enyne substrates.Because of the different nucleophilicity of phosphoryl radicals,variant results were obtained after cyclization,and diphenyl phosphorus oxides revealed high chemoselectivity and regioselectivity in this reaction.Chapter ?:In chapter 4,we have achieved the rearrangement during the alkynyl addition and oxidative cyclization process with phosphoryl radicals.Six-member ring intermediate or transition state were formed.After desulfurization and 1,5-aryl migration,newly formed cinnamamidyl radical continued cyclizing to give phosphorus-contained spiro-quinone derivatives.This reaction exhibited high regioselectivity because of the electronic effect on benzene ring.Also,we synthesized substituted quinolinone derivatives by changing substituent group on substrates.Chapter ?:In chapter 5,we completely explained the definition of Azaborines compounds and features of B-N bonds.Also,the functions and application value of Azaborines compounds were introduced from four aspects: the improvement of ligand in the metal complex,the development of hydrogen storage materials,the synthesis of polymer and new nano-materials and the potential in biological medicine research.Finally,we also introduced the way to three different types of Azaborines and their derivatives.Then,we have developed the synthesis of new naphthalinic Azaborine derivatives by employing trifluoroborates potassium and silicon tetrachloride.After analyzing the influence of nitrogen heterocycle toward the reaction process,we confirmed the optimal conditions by adding extra silicon tetrachloride and increasing the temperature.A series of highly-functional Azaborine compounds with special electronic properties were gained,avoiding acute conditions such as microwave and improving the tolerance of substrates dramatically.