C(sp~2)-S And 1,2-di C(sp~3)-Br Bonds Formation Via C-H Oxidative Reaction

Hydrocarbons exist widely in nature.In recent years,the study of C-H bond oxidation functional groups had developed rapidly.Chemists usually use transition metals to catalyze the oxidation of C-H bond functionalization reactions,however,such methods require precious metal catalysts;excess alkali or non-green oxidants are not environmentally friendly and economic.How to achieve more green,economical and efficient C-H bond conversion is a challenging subject in the field of chemical research.In this thesis,the two reactions of indole sp² C-H bond oxidation to indole sulfide and 1,2-disubstituted aryl both sp³ C-H bond oxidation to1,2-dibromoarylalkane were studied in depth.The main contents of this work consist of three parts:1.The direct oxidation of C-H bond can transform energy at high value,and has the characteristics of high atom and step economy.By using direct conversion of different types of carbon-hydrogen bonds,a simpler,economical and efficient synthesis route can be designed.The well documented research of the oxidation reaction of sp²C-H bonds to construct C-S bonds and sp³ C-H bonds depicted that the organic sulfides and organic halides are an important class of intermediates.If the C-S and C-halogen bonds can be constructed by direct C-H bond oxidation,the reagents and raw materials for pre-functionalization will be reduced dramatically.2.As to our knowledge,it's the first time,an indole sulfide reaction catalyzed by I₂/MnO₂ and oxygen oxidation was established in this work.Various indole sulfide compounds were efficiently synthesized using indole and thiol as substrates and anisole as solvent.This method has the advantages of mild conditions,simple and convenient operation,and good functional group tolerance.Also,this method can easily employeed to synthesize anticancer and anti-AIDS drugs,especially for cutting down the existing synthetic routes.Detailed mechanism experiments and computational chemistry experiments has shown that the reaction undergos a single electron transfer process.The anisole not only act as a solvent,but also promote the reaction.3.Here we also established a reaction to synthesize 1,2-dibromoarylalkane by double sp³ C-H bond oxidation for the first time.The readily available N-bromosuccinimide is used as a source of bromine and the additional catalysts and additives were no longger required.By using a variety of 1,2-disubstituted arylalkanes as substrates,more than twenty 1,2-dibromo compounds were synthesized.The obtained target products can be further converted into various organic fine chemicals.Mechanism experiments show that benzyl bromide is a possible intermediate,more detailed research is still in progress.