| Alkenes/alkynes are simple and readily available fine chemicals that are widely used in synthetic chemistry,pharmaceuticals,materials and other fields.The bifunctionalization of alkenes/alkynes is an important tool for the rapid and efficient construction of complex drug molecule structural units.There are many kinds of olefin/alkyne bifunctionalization reactions,and phosphorus-mediated olefin/alkyne bifunctionalization is of great significance for the construction of organophosphorus compounds with important biological activities.In recent years,several strategies have been developed,but these strategies are often limited by the generation of a lot of chemical waste,and the use of transition metal catalysts,stoichiometric redox reagents,which restrict the further application of these synthetic strategies.In view of this,the development of metal-free,non-additive redox reagents,efficient and environmental friendly synthesis strategies have been focused.Organic electrochemistry is the study of chemical reactions which involve the activation of organic molecules by"traceless"electron transfer.Based on this,various selective bifunctionalization of olefins and alkynes with phosphorus oxide as the phosphorus source have been successfully achieved under the electrochemical conditions in this thesis.Initially,the carbonylated phosphorylation of alkenes/alkynes was deliveried using the anode/~-OAc dual-catalytic strategy.Whereafter,the convergent paired electrolysis strategy has been developed to access the hydrogenated phosphorylation of electron-deficient alkenes/alkynes.These methods provide an efficient,mild,and green electrochemical synthesis method for the various ofβ-carbonyl phosphine oxides andγ-carbonyl phosphine oxides with high added value.Besides,the sulfonylated hydroquinone has been deliveried by employing electrochemical in situ oxidation strategy.The thesis include the following parts:(1)A metal-and exogenous-oxidant-free oxidation-induced oxyphosphorylation of alkenes and alkynes with water forβ-ketophosphonates has been developed through the radical coupling under electrochemical conditions.This protocol is compatible with a wide range of alkenes,alkynes,and diarylphosphorus derivatives,and enables the gramscale synthesis ofβ-ketophosphonates.The mechanistic study revealed that the P radicals were generated via hydrogen atom transfer(HAT)event jointly mediated by ammonium tetrabutylacetate and anode oxidation process.(2)A straightforward and practical strategy for hydrophosphorylation of electron-deficient alkenes and alkynes to accessγ-ketophosphine oxides,enabled by a convergent paired electrolysis(CPE)in the absence of a metal,base,and redox reagent,has been described.Mechanistic studies have revealed that the diarylphosphane oxides play the dual role of a phosphorus radical precursor and hydrogen donor in this transformation.(3)The electrochemical in-situ oxidative sulfonylation of phenols with sulfinic acids access to sulfonylated hydroquinones has been developed.The method does not need any exogenous oxidant and metal catalyst,and provides a mild and simple method for the preparation of sulfonylated hydroquinones.Notably,such an electrochemical in-situ-oxidative synthetic strategy presented wide functional group tolerance and amenability to gram-scale synthesis with62-80%yields. |
