| Unsaturated hydrocarbons are bulk products produced by cracking in the petroleum industry.Therefore,the development of unsaturated hydrocarbon conversion has always been a hot topic in organic synthesis and petrochemical research.The difunctionalization reaction of unsaturated hydrocarbons is one of the most important and popular methodologies in organic synthetic chemistry.In recent years,the difunctionalization reaction of unsaturated hydrocarbons has emerged as an effective and straightforward strategy to increase molecular complexity,and has been well established,which ongoing attracts much attention for organic synthetic chemists.This reaction allows incorporation of two new functional groups to a single molecule,thus building two new chemical bonds in a single reaction with high atom economy and efficiency.Transition metal-catalyzed unsaturated hydrocarbon 1,2-or 1,4-difunctionalization reactions were well studied,which are focused on the use of nickel or copper as the catalyst.To date,much attention on two types of unsaturated hydrocarbon difunctionalization reactions has been attrached,including:One is the two-component unsaturated hydrocarbon difunctionalization reaction involving an intramolecular cyclization process,which represents an effective approach for the preparation of heterocyclic compounds;the other involves the three-component difunctionalization of unsaturated hydrocarbons.This thesis is based on the study of nickel-or copper-catalyzed difunctionalization reactions,and the following four aspects are carried out for detailed elaboration.(1)Recent progress in the nickel or copper catalyzed difunctionalization of unsaturated hydrocarbon were reviewed systematically.The experimental results and mechanisms involving nickel-catalyzed reductive difunctionalization reactions,copper-catalyzed difunctionalization reactions and nickel/photoredox-catalyzed difunctionalization reactions are discussed and summarized in detail.(2)A nickel-catalyzed arylcarbamoylation reaction of alkenes of N-(o-haloaryl)acrylamides with CO and nitroarenes via reductive aminocarbonylation to produce carbamoyl-substituted oxindoles with an all-carbon quaternary stereogenic center is developed.Starting with N-(o-haloaryl)acrylamides,simple CO,and inexpensive nitroarenes and using a Ni catalyst,a dinitrogenbased ligand,a Zn reductant,a TMSCl additive,and a base system,this protocol enables the synthesis of various carbamoylsubstituted oxindoles and allows the efficient late-stage derivatization of valuable molecules.(3)A new fluoroamide-driven intermolecular hydrogen atom transfer(HAT)strategy for copper-catalyzed intermolecular 1,2-alkylarylation of alkenes with carbazates and various arene nucleophiles,such as indoles,pyrroles and 1,3,5-trimethoxybenzene,is described.By manipulating N-(tert-butyl)-N-fluoro-3,5-bis(trifluoromethyl)benzenesulfon-amide(NFBS)as the intermolecular HAT reagent,this reaction enables the generation of the carbazate nitrogen-centered radicals through intermolecular HAT followed by decomposition to form the alkyl radicals,radical addition across the alkene,single electron oxidation and nucleophilic coupling cascades to achieve the alkene 1,2-alkylarylation.(4)A cooperative nickel and photoredox reductive catalysis for1,4-dicarbofunctionalization of 1,3-enynes with alkylamines and organohalides for stereoselective access to tetrasubstituted allenes is presented.The reaction enables the formations of two new C-C bonds,including a C(sp~3)-C(sp~3)bond and a C(sp~2)-C(sp~2)bond,through the photocatalytic aminoalkyl radical generation,radical addition across the C=C bond,isomerization,single-electron oxidation of Ar X with the allenyl-Ni intermediate(generated from oxidatve addition of the active Ni~0 species with radical of allene)to form the allenyl-Ni(Ar)Br intermediate,reductive elimibation to form the desired tetrasubstituted allene proudcts and the Ni~I species and regeneration of active Ni~0 species by the photoreduction cascades. |
PDF Full Text Request