Fluoroamide Directed α And δ C-alkylation Of Nitroalkanes

Nitro compounds are of prime importance in organic,it also has extensive applications in drugs and materials.Therefore,the synthesis and expansion of its derivatives are particularly important.Due to the strong electron-withdrawing effect of nitro groups,theα-C–H bond is prone to deprotonation.Therefore,activated nitronate anions can participate in various C–C bond formation processes through single electron reaction and double electron reaction.The double reaction mainly involves Michael addition,(nitro)Mannich reaction,Henry reaction and nucleophilic substitution reaction.The single electron reaction mainly uses a catalyst to achieve nitroalkylation of the carbon halide bond.Unfortunately,there have been no reports of regioselective nitroalkylation of inert hydrocarbon bonds through single electron reactions.In order to overcome the difficulty of highly selective functionalization of hydrocarbon bonds,nitrogen center radicals provide a novel idea for the functionalization of specific C(sp~3)-H bonds through intramolecular hydrogen atom transfer(HAT).Herein,by exploiting different activation modes of fluoroamides,α-andδ-C(sp~3)–H alkylation of nitroalkanes was achieved with predictable and switchable regioselectivity.This thesis mainly conducts research from the following two aspects:1.Under the action of copper catalyst,fluoroamides undergoes a single electron transfer to produce nitrogen center radicals,which generatedδCarbon free radicals by intramolecular hydrogen atom transfer,and then it realizedδAlkylation of inert C-H bonds at position by the action of copper catalysts.This reaction has a broad substrate scope and good functional group tolerance.2.Under alkaline conditions,fluoroamides generate an imine intermediate in situ and it is subsequently nucleophilic addition by activated nitroalkane anions.This reaction also has a wide substrate range and good functional group tolerance.