Study On The Nucleophilic Addition Reaction Of Alkyl Bromides With Carbon-Nitrogen Double Bond Promoted By Tin Powder

In this thesis,we have studied the nucleophilic addition reaction of brominated hydrocarbons and carbon-nitrogen double bond promoted by tin powder,and a series of α-allyl glycine esters were synthesized.This method uses tin powder and allyl bromide to produce organotin reagent in situ to participate in the reaction,which not only keeps the advantages of organotin reagent,but also avoids the tedious preparation process of organotin reagent,and reduces the environmental pollution in the reaction process.In addition,the difluoromethylation of quinoxalinones promoted by tin powder was also studied.3,4-Dihydroquinoxaline-2(1H)-ones,as a class of nitrogen-containing heterocycles,widely exists in natural products and drugs.Tin powder promoted difluoromethylation of quinoxaline ketones provides a new method for the synthesis of 3-difluoromethyl-3,4-dihydroquinoxaline-2(1H)-ones,which have potential biological activity.This thesis includes the following three parts:Chapter One: Research progress of alkyl bromides in organic synthesisIn this chapter,we reviewed the research progress of alkyl bromides in organic synthesis in recent years.We mainly reviewed the research progress of alkyl bromides,such as allyl bromides,ethyl bromodifluoroacetate,bromoacetonitrile and other brominated hydrocarbons,in coupling reaction,addition reaction and free radical reaction.Chapter two: Tin powder promoted synthesis of α-allyl glycinate compoundsThis chapter explores the "stepwise one-pot" synthesis of γ,δ-unsaturatedα-amino acids from ethyl glyoxylates,amines and allyl bromides promoted by tin powder.The method has the advantages of cheap and readily available raw materials,mild reaction conditions,simple operation,wide substrate applicability,and high yield.This method provides a new method for the synthesis ofγ,δ-unsaturated α-amino acid compounds.Chapter three: Study on the difluoromethylene reaction of quinoxalinone compounds promoted by tin powderThis chapter explores the “one-pot” synthesis of 3-difluoromethyl-3,4-dihydroquinoxaline-2(1H)-ones promoted by tin powder using ethyl bromodifluoroacetate as difluoromethylation building block.The method has the advantages of cheap and readily available raw materials,mild reaction conditions and simple operation.This method provides a new method for the synthesis of3-difluoromethyl-3,4-dihydroquinoxaline-2(1H)-one derivatives,and expands the application of ethyl bromodifluoroacetate as difluoromethylene building block in organic synthesis.