Research Of Aromatic And Alkene Nitration

This dissertation focuses on exploration of novel nitration reactions of aromatics and alkenes,which mainly includes the following four parts:1.We have developed a novel radical cross coupling strategy using TBN as the nitro source and CAN as the oxidant,and quickly established a nitrating reagent library with 28 members,laying the foundation for the discovery of a new generation of nitrating reagent.This mild,acid-free and scalable protocol was compatible with a wide array of substrates with good functional group tolerance.Furthermore,by following this nitration protocol,dinitration of sulfonamide derivatives and efficient late-stage C-H nitration of anti-HIV drug efavirenz was realized.2.We discovered a new type of nitrating reagent（5-Methyl-1,3-dinitro-1H-pyrazole）behaved as a controllable source of the nitronium ion in a N-nitro reagent library through evaluating the nitrating ability.Mono-nitrated or di-nitrated products could be selectively furnished by manipulating the reaction conditions,and mononitration of more challenging deactivated electron-deficient substrates and drug molecules was realized.This protocol features good atom economy,mild conditions,wide substrate scope,excellent functional group tolerance,recyclability of nitrating reagent precursors and scalability.DFT calculations and preliminary mechanistic study revealed that the powerfulness and versatility of this nitrating reagent is due to a synergistic“nitro effect”and“methyl effect”.3.Preliminary studies of arenes nitration was conducted via electrochemical oxidation strategy.Using n Bu₄NNO₂ as cheap and readily available nitro source and acetone-hexafluoroisopropanol as mixed solvent,the target product could be obtained in 18%GC yield with a constant current electrolysis mode.Furthermore,A series of TEMPO-derived nitrating reagents were synthesized,excellent thermal stability and irreversible electrochemical oxidation made it possible as a candidate nitrating reagent for electrochemical nitration.4.A highly stereoselective and efficient protocol for the synthesis of nitroalkenes was developed through nucleophilic nitration using inexpensive commercial reagent Na NO₂ as nitro source.This protocol features widely accessible starting materials,simple operation,scalablity and a variety of substrates,including monosubstituted alkenes,disubstituted alkenes,conjugated dienes could be nitrated regio-and stereoselectively,providing a general platform for the diversified synthesis of nitroalkenes.