Nickel-Catalyzed Regio-and Enantioselective Hydromonofluoromethylation Of 1,3-Dienes Or 1,3-Enynes

This thesis aims to develop the highly regio-and enantioselective hydromonofluoromethylation of 1,3-dienes or 1,3-enynes with fluorobis（phenyl-sulfonyl）methane by using low-cost chiral nickel catalysis,which allowed to construct value-added monofluoromethylated compounds featuring a carbon stereocenter or axial chirality.The detailed research works include the following:1)By using a combination of Ni（COD）₂ and P-chiral ligand（S,S）-Quinox P*,an unprecedented regio-and enantioselective hydromonofluoromethylation of 1,3-diene with fluorobis（phenylsulfonyl）methane is established,providing an efficient and atom-economical route to access monofluoromethylated allylic products with excellent 4,3-Markovnikov regioselectivities and enantioselectivities.The salient features include broad substrate scope,good functional group tolerance,mild base-free conditions.Moreover,a tandem Ni-catalyzed asymmetric hydromonofluoromethylation and subsequential Mg-enabled reductive desulfonylation process is developed for the enantioselective construction ofα-CH₂F or CD₂F substituted chiral allylic compounds that are difficult to access by other method.Preliminary mechanism studies revealed thatπ-allyl nickel species might be the key intermediate,the proton source of the product mainly comes from both ethanol and fluorobis（phenylsulfonyl）methane.2)The first regio-and enantioselective hydromonofluoromethylation of 1,3-enyne with fluorobis（phenylsulfonyl）methane is accomplished by using（R）-Me O-BIPHEP ligated Ni（COD）₂ complex,which could afford various fluoromethyl-tethered axially chiral allenes with excellent regio-and enantioselectivities.Diethyl fluoromalonate proves to be a suitable monofluoroalkylated reagent.The practicability of this method is further highlighted by its broad substrate scope,mild condition,gram-scale synthesis and diversified elaborations of product.Additionally,β-CH₂F or CD₂F substituted chiral allenes are readily achieved through merging the Ni-catalyzed asymmetric hydromonofluoromethylation with a reductive desulfonylation reaction.