The Application Of C-H Functionalization In Modification Of Quinolines

As the important organic compounds,quinolines play a significant role in the fields of pharmacy,printing and dyeing as well as optoelectronic materials,especially fluorine-containing quinolines,have received extensive attention of chemists due to the unique bioactivity,lipotropy and metabolic stability.However,there are many disadvantages in the traditional preparation methods of quinolines,such as complicated preparation procedure,harsh reaction conditions,poor site-selectivity and serious environmental pollution.Hence,the establishment of efficient green approaches for the preparation of quinolines is all-important.We discovered a novel strategy that catalysts controlled selectivity in synthesis of C2-and C3-sulfonate esters.Owing to the structure of product can not be verified through ¹H?¹³C NMR and HRMS,therefore,further confirmation was made by X-ray diffraction.In the meantime,the influence factors including additive type and solvents type were discussed in order to obtain better reaction condition,and 26 compounds were prepared.The study provides a favourable method for the synthesis of sulfonic acid ester derivatives which contain quinolines.Finally,the recyclability of CS@CuI was proved through cycling experiment.According to the catalytic activity and recyclability of homemade catalyst CS@Cu,the C-CF3 cross-coupling reaction was researched,and the CF3 group was introduced into quinolines at C5 position.Subsequently,the control experiments containing kinetic isotope effect,radical inhibition as well as radical trap were designed and performed to demonstrate that a single electron transfer mechanism was involved.In addition,it was also verified that the activity of the catalyst remained stable after 5 times of recycle.The feasibility of direct perfluoroalkylation of quinoline at C5 position was investigated,and the reaction was realized in the absence of any transition metal catalysts through deep analysis of the mechanism.Besides,the oxidant species,additive type and reaction time for the perfluoroalkylation reaction were screened,31 compounds were synthesized and chemical structure was confirmed via X-ray diffraction.Our work offered a simple and efficient method for the preparation of quinolines which contain perfluoroalkyl group.*All compounds were adequately verified by ¹H NMR,¹³C NMR?19F NMR and HRMS.