Inerdisciplanery Study Inspired By Radical Reaction Of Substituted Hantzsch Ester And Electrochemical Reduction Reaction

Green Chemistry contains the requirements for material and energy,which are unified in the process of chemical reaction.With the development of the national economy,the requirements of green chemical production technology are increasing.Green chemistry is the research field to realize environmental protection,energy saving and sustainable development of chemical industry.In recent years,green chemistry has become the core scientific problem in the demand of national green development.Therefore,the development of new green chemical synthesis methods has become the forefront of organic synthesis research.The development of organic free radical chemistry has lasted for more than a century.Due to its unique structural characteristics,it has mild and high reactivity in chemical reactions.Substituted Hantzch esters can produce free radicals efficiently under various conditions without high pollution reagents,and are widely used in a series of green transformation.This paper is based on the research of substituted Hantzch esters.As a clean secondary energy,electricity has great significance in the theory and application of organic synthesis by its unique redox characteristics.In recent years,with the in-depth study of mechanochemical reaction mechanism and the improvement of reaction equipment,this method has been widely used and become one of the research hotspots in organic synthesis.In this paper,based on the research inspiration of free radical chemistry and electrochemistry of substituted Hantzch esters,cross research work has been developed.This thesis mainly includes the following parts:1.Application of Hantzsch Ester and Meyer Nitrile in Radical Alkynylation ReactionsWe report the first application of substituted Hantzsch ester and Meyer nitrile in the formation of Csp-Csp3 bonds.With K₂S₂O₈ as initiator,substituted dihydropyridine released an alkyl radical to react with BI-activated alkyne.The corresponding 1,2-disubsituted acetylene was obtained in up to 97%yield.By applying Meyer nitrile as an alkyl radical donor,intermolecular construction of a quaternary carbon center was fulfilled.2.Chemical-Reductant-Free Electrochemical Deuteration Reaction using Deuterium OxideWe report a protocol for electrochemical deuteration of?,?-unsaturated carbonyl compounds under catalyst-and external reductant-free conditions with deuteration rates as high as 99%and yields up to 91%in 2 h.The use of graphite felt for both the cathode and the anode was key to ensuring chemoselectivity and high deuterium incorporation under neutral conditions without the need for an external reductant.This protocol has a number of advantages over previously reported deuteration reactions that use stoichiometric metallic reductants.Mechanistic experiments showed that O₂ evolution at the anode not only eliminated the need for an external reductant but also regulated the p H of the reaction mixture,keeping it approximately neutral.3.Electrochemical Reduction of Polysubstituted PyridineBy using sacrificial anode method,the deasterification and rearrangement of polysubstituted pyridines were realized for the first time to synthesize total substituted pyrrole compounds.The cheap zinc was used as anode and graphite felt as cathode.The reaction was carried out smoothly with the characteristics of continuous electron generation under the electrode.The reaction conditions were mild and the substrate compatibility was good.The mechanism study shows that water as the hydrogen source,solvent does not participate in the reaction.