Study On Chlorination Of Aromatic) C(sp~2)-H Bond

Aryl chlorides are important intermediates in the synthesis of natural products,functional materials and pharmaceutical molecules.Therefore,highly regioselective synthesis of aryl chlorides under mild reaction conditions has always been a concern of chemists.Direct chlorination of C（sp²）-H bond is the simplest and most efficient means for this purpose.This thesis focuses on the research on direct C（sp²）-H bond chlorination of aromatic compounds.It is divided into three parts:The first chapter summarizes the research progress on direct chlorination of C-H bonds in the past twenty years,and the literature is introduced from the aspects of（hetero）aromatic C（sp²）-H chlorination and aliphatic C（sp³）-H chlorination based on the C-H bond types.The second and third chapters cover the research work during the master’s program,and the results obtained are summarized as follows:（1）Selective C5 monochlorination and C5,C7 dichlorination reactions of 8-amidoquinolines were achieved by using ^tBu OCl as the electrophilic chlorinating reagent in a simple reaction system at close to room temperature without additives.Adding a catalytic amount of Cu（OTf）₂ to the reaction system can significantly shorten the reaction time and increase the conversion rate of dichloro reactions.This method is tolerant of multiple functional groups.（2）Cu（OTf）₂ was selected as a low toxic and cheap copper catalyst to realize the ortho monochlorination of 2-phenylpyridine with ^tBu OCl as the chlorinating reagent.It was found that the addition of 3,4,7,8-tetramethyl-phenanthroline and acetic acid can improve the reaction yield.The reaction does not require high temperature heating or additional oxidants.