| Radical reaction is one of the important reaction types in organic synthesis reactions.Compared with the traditional polar/ionic reaction,radicals,as an active intermediate,participate in the breaking and reconstruction of chemical bonds in a controllable and efficient way,which can be also applied to the construction of complex molecules.However,the radical reaction still faces the challenge of how to generate and capture radicals.Alkylsilyl peroxides,as alkyl radical precursor,have mild reaction conditions compared with traditional organic peroxides.They are easy to prepare and store,and can produce a variety of alkyl radicals（primary carbon,secondary carbon and tertiary carbon alkyl radicals）,and to form the C-C,C-N,C-O,C-B,C-Si bonds.To further explore the functionalization of alkyl radicals,In this thesis,alkylsilyl peroxides have been utilized as alkyl radical precursors.Under the catalysis of Cu,Fe and other metals,the single electron transfer process occurs to generate alkyl radical in situ,and a series of functionalization studies are carried out on alkyl radical,including C-C bond,C-N bond and C-halogen bond formations,as well as the synthesis strategy of three-component reaction of vinylarenes with alkyl radical.This thesis mainly includes the following three parts:1.A synthetic method development has been developed for the coupling reaction between TMSX（X = CN,N3,Cn F2n+1）and carbon radicals generated in suit by the Cu I catalyzed selective cleavage of various alkylsilyl peroxides.This method realizes cyanidation,azideization and perfluoroalkylation of alkyl radicals under mild conditions at room temperature.The scope of substrates has broad adaptability,including 5-membered,6-membered,7-membered and 12-membered cyclic alkylsilyl peroxides,a certain biologically active hypoglacial flake ketones,theobromine-derived alkylsilyl peroxide,afforded the corresponding in good to high yield（22%-99%）.2.On the basis of above-mentioned transformation,we have further developed the coupling reaction between alkyl hydroperoxide and TMSX（X = CN,N3,CF3,Cl,Br,I）catalyzed for cyanidation,azidation and halogenation of alkyl radicals under mild condition.Different cyclic alkyl hydroperoxide substrates have broad adaptability and the corresponding target compounds were obtained in 27%-99% yields.The study of reaction mechanism shows that alkyl hydroperoxide generates alkylsilyl peroxide in situ,which greatly improves the atomic economy efficiency and provides a theoretical and experimental basis for industrial application.3.Using alkylsilyl peroxide as alkyl radicals precursors,we have developed a new strategy for the formation of two carbon-carbon bonds using vinylarenes with alkylsilyl peroxides and β-keto carbonyl substrates in the presence of Fe（OTf）2 under mild conditions.In this approach,all kinds of substrates have good adaptability,several different alkylsilyl peroxides in situ to generate primary carbon,secondary carbon alkyl radicals,a variety of vinylarenes with different substituents substituents（electron-withdrawing groups,electron-donating substitutions and o-,meta-substituents）and β-keto ester compounds were investigated,with a yield of 48%-94% for the corresponding coupling products.In the transformation application,the cross-coupling of alkylsilyl peroxide,2-hydroxystyrene and methyl acetate were used to synthesize benzopyran derivatives in yield of 48% in two steps,which provided a new strategy for the synthesis of benzopyran derivatives.In summary,we have developed a new strategy for the formation of C–C or C–N bonds between Me3 Si X（X = CN,Cn F2n+1（n = 1–4）,and N3）and carbon radicals generated in situ by the copper-catalyzed selective cleavage of various alkylsilyl peroxides.On this basis,alkylsilyl peroxides were generated in situ from the corresponding alkyl hydroperoxides using organosilicon compounds of the type Me3 Si X（X = CN,N3,and halogens）and an amine base.Subsequent in situ copper-catalyzed homolytic cleavage of the alkylsilyl peroxides afforded alkyl radicals,which were then trapped with X（X = CN,N3,and halogens）to furnish products with new carbon-carbon,carbon-nitrogen,or carbon-halogen bonds in good to high yields.In addition,we have developed a new strategy for the formation of two carbon-carbon bonds using vinylarenes with alkylsilyl peroxides and β-keto carbonyl substrates in the presence of catalytic Fe（OTf）2 under mild conditions. |
