The Research On Electrochemical Oxidative Difunctionalization Of Alkenes And Selenylation Of Heteroaromatic

Alkenes,as a commonly used synthetic feedstock,occupy an important position in organic synthesis.The 1,2-difunctionalization of alkenes has becoming an important methodology for accessing complex molecules from simple starting materials.In the reactions,the unactivated carbon-carbon double bonds are mainly converted into two new chemical bonds through a process mediated by oxidation radicals.Various starting materials,such as nitriles,amines,alcohols,aldehydes,peroxides and aryl sulfinates,were suitable reagents so for in the 1,2-difunctionalization of alkenes.The fundamental challenges of the transformations are how to enhance the reactivity and control the selectivity.With the development of electrochemistry in recent years,electrochemical oxidation strategy has becomimg one of the most important processes in organic synthesis.The electrochemical reactions use electron as green oxidant under external-oxidant-free conditions.Generally,hydrogen,which is a clean energy source,is released as byproduct of the reaction during the reaction.Firstly,we highlighted recent advances in the intermolecular 1,2-difunctionalization of alkenes,including 1,2-dicarbofunctionalization,1,2-carboheterofunctionalization and 1,2-diheterofunctionalization.On the basis of literature research,the electrochemical method is used to design the route of the electrochemical difunctionalization reaction of alkenes.This article mainly obtains the research results:1.Developed high-efficiency electrochemical alkylene oxide amiselenization and oxyselenization reactions,which can be carried out at room temperature without any additional additives(acids,oxidants or transition metals),which is a synthetic phenyl selenization molecule provides a green way.In the amiselenization,secondary phenylalkyl amines can act as a reaction component to generate aminated products which are difficult to make via known methods.Alkylselenoethers are also suitable for this system.This reaction represents a breakthrough to the limited intermolecular selenide difunctionalization and improves the potential of this protocol for the use in the pharmaceutical industry.2.Through electrochemical Se-Se bond activation,the diselenide is completely converted into free radicals in the Se center.The use of styrene to capture RSe radicals successfully achieved the three-component free radical carbon selenization,and the reaction was efficient and rapid,which provided a green way for the synthesis of arylselenyl molecules and alkylselenyl molecules.Using this atomic economy scheme,the diversity of aryl-alkyl and alkyl-alkyl selenoethers is regioselectively obtained,which has potential applications in biochemistry.Both thiophene and furan can participate in the electrochemical bifunctionalization of alkenes,which provides an effective way for compound synthesis.The key features of this benign and robust protocol are:(1)electrochemical approach;(2)atom-economic;(3)non-toxic and easily handleable reagents;(4)regioselective.3.We reported the electrochemical oxidative selenylation of activated arenes,and the direct coupling of RSe radicals and activated arenes to form asymmetric aryl-arylselenoethers.This reaction was carried out in an undivided electrochemical cell with tetraethylammonium tetrafluoroborate as the electrolyte.Using this benign,atom-economic protlcol,the desired selenylated products were obtained regioselectively,in good to excellent yields,using a half molar equiv.of the diselenides.We have developed an alternative,synthetically attractive,robust and safe scalable method for the synthesis of selenylated arenes via electrochemically oxidative C(sp~2-H) bond selenylation.