Reductive Aromatic C-H Allylation Of N-Benzylsulfonimides

The reaction of benzyl electrophiles with nucleophiles usually occurs at the benzyl position while sporadic examples have shown that it can be carried out on the aromatic ring.Under the condition of transition metal catalysis,nucleophiles that can conduct C-H allylation reaction with benzyl electrophiles on the aromatic ring includes allyltributylstannane,allylsilanes,allyl pinacolboronate and allyl Grignard reagent,which require pre-preparation,toxic,and/or incompatible with moisture and air.In this thesis,reductive aromatic C-H allylation between benzyl electrophiles and allyl electrophiles was developed without pre-preparation of allyl organometallic reagents.Chapter 1:Research progress of aromatic ring coupling reaction involving benzyl electrophiles and reductive coupling reaction involving allyl electrophilesThis chapter describes transition metal catalyzed regioselective C-H functionalization of arenes between benzyl electrophiles and different types of nucleophiles,and the reductive coupling reactions involving allyl electrophiles.Firstly,the highly regioselective aromatic C-H allylation reactions of allyl organometallic reagents such as allyltributylstannane,allyl pinacolboronate,allylsilanes and allyl Grignard reagents with benzyl electrophile via the process ofπ-benzyl palladium intermediate are emphatically introduced.Besides,the reduction coupling reaction involving allyl electrophiles is presented which leading to the reductive allylation of electrophiles such as aryl halides,alkenyl halides and benzyl halides in the presence of transition metal catalyst such as palladium,cobalt and nickel.Zinc,manganese,indium and magnesium can be applied as reductants in this reaction.This kind of reaction avoids the preparation of allyl organometallic reagents in advance,simplifies the reaction operation,and complements traditional cross coupling reactions.Chapter 2:Reductive aromatic C-H allylation reactions of N-benzylsulfonimides with allyl estersWe have developed a reductive aromatic C-H allylation reaction using allyl esters to generate allyl organometallic reagents in situ under reducing conditions with benzyl electrophiles and allyl electrophiles.In the presence of 10 mol%tris(dibenzylideneacetone)dipalladium-chloroform adduct,40 mol%tri(4-fluorophenyl)phosphine,3 equivalents of indium as a reductant,1 equivalent of DBU,and 2 equivalents of lithium chloride,a series of N-(2-thienylmethyl)sulfonimides,N-(2-furanmethyl)sulfonimides,and N-(1-naphthyl)sulfonimides were underwent high regioselective reductive aromatic C-H allylation reaction with allyl acetate at 80℃ or 100℃ to yield 2-allylheteroaromatic hydrocarbon and 1-allylnaphthalenes with medium to excellent yields in N,N-dimethylformamide.This reaction allows the use of inexpensive allyl esters to implement the reductive aromatic C-H allylation of N-benzylsulfonimides,thus avoiding the preparation of allyl organometallic reagents in advance,simplifying experimental operations,and expanding the range of aromatic C-H allylation reactions of benzyl electrophiles.