Study On 1,2-Dialkylation/Defluoroalkylation Of Olefins Induced By Visible Light

In recent years,visible light catalysis has a wide prospect in the field of organic synthesis owing to its unique redox properties,green and mild reaction characteristics.Compared with traditional transition-metal catalysis,this strategy is more economical and efficient,and has good functional group compatibility.Olefins,as a class of important chemical raw materials,are the most commonly used C2 synthons in organic synthesis.The functionalization of olefins can directly and efficiently introduce various functional groups to build complex molecules,which have extensive application in the area of biology,pharmacology and fine chemicals.This article is divided into the following three chapters:ChapterⅠThis chapter is divided into two sections to summarize the relevant reports in recent years,the first section mainly outlines the research progress of dicarbofunctionalization of alkenes from transition metal catalysis and photocatalysis;the second section briefly introduces the importance of fluorinated compounds and summarizes the photo-catalyzed defluorination functionalization of trifluoromethyl alkenes.ChapterⅡWe proposed a photoredox-neutral 1,2-dialkylation of active alkenes,in which two C(sp~3)-C(sp~3)bonds were constructed in one-pot.We obtained a series of Grignard analogues with two tertiary centers,avoiding the drawbacks of conventional Grignard reaction.Among these,alkyl oxalate salts as radical precursors first underwent Giese addition to alkenes,followed by reductive radical-polar crossover(RRPCO)process.This photoredox strategy further demonstrates the synthetic potential of alcohols as radical sources,and also complements functionalization reactions of alkenes.ChapterⅢIn this chapter,we selected alkyl boronic esters as the radical source,and combined with the amino radical transfer(ART)strategy to explore the visible light-catalyzed defluoroalkylation ofα-trifluoromethyl alkenes.By screening and optimizing the factors affecting the reaction,we found the optimal reaction conditions and investigated the applicable scope of olefins.In addition,the result of control experiments showed that the reaction could also be carried out in air.