Studies On The Construction Of Csp~3–Csp~3 Bonds By Nickel Catalysis

Transition metal-catalyzed cross-coupling reaction is one of the most important methods for constructing carbon-carbon bonds.Compared to other types of carbon-carbon bonds formation,Csp~3–Csp~3 cross-coupling reaction has a wide range of application in organic synthetic chemistry.And it also provides important synthetic method for natural products and drugs.Therefore,Csp~3–Csp~3 cross-coupling reaction has obtained wide attention by chemists.This thesis focuses on the application of C–O electrophiles and unactivated alkenes in nickel-catalyzed cross-coupling reactions to develop new methods for the construction of Csp~3–Csp~3 bonds,which mainly includes the following three parts:1.Progress on nickel-catalyzed Csp~3–Csp~3 cross-coupling reactions has been introduced mainly from three aspects:alkyl nucleophiles,olefins and alkyl electrophiles.2.We developed a reductive nickel-catalyzed cross-coupling of benzyl oxalates with alkyl bromides,using oxalate as a new leaving group.This reaction has excellent functional group compatibility and wide substrate scope,which provides a brand-new perspective for the application of transition metal-catalyzed C–O bond activation in reductive cross-coupling.3.We explored a reductive nickel-catalyzed cross-coupling of unactivated alkenes with alkyl bromides.Linear-products could be obtained with high regioselectivity.However,substrate containing an NH group as a directing group could obtain a mixture of linear and branch products(l/b=4:1).Based on this result,highly regioselective synthesis of the branch-products is possible by further modification of the substrates.