Asymmetric Allyl Alkylation Of Carboxylic Acid And Allyl Carboxylates Co-catalyzed By Photoredox And Palladium

As we all know,human beings cannot survive without energy.With the rapid development of modern society and economy,the demand for energy is also increasing.However,various traditional energy resources,such as natural gas,oil,and coal,are becoming eventually exhausted,and there are many unreasonable situations in the use of these traditional energy sources.To solve on these problems,scientists have been researching and exploring a sustainable green energy.Scientists gradually shifted their focus to solar energy,a natural and sustainable energy source.Plants can use photosynthesis to convert light energy into chemical energy,so people can also use solar energy to convert into chemical energy to achieve the purpose of energy transfer and improve its conversion efficiency.Therefore,in the field of chemical research,photochemistry quickly became a hot spot for scientists.Redox Processes in chemical reactions are widespread,and can be promoted by the interaction of photosensitizers and visible light.Single-electron transfer process can generate free radical ions,free radicals and other highly reactive intermediates to participate in further reactions.This strategy has been continuously applied in modern organic synthetic chemistry in recent years.However,the free radicals and other intermediates produced in the reaction generally have the characteristics of high activity and instability,which leads to poor selectivity of the reaction,especially stereoselectivity.This has become an urgent focus and difficulty in the visible light catalytzed redox reaction.The synergistic effect of chiral catalysts and photosensitizers is the major stategy to achieve stereoselectivity of photo-induced radical reactions.This thesis studies the synergistic effect of transition metal palladium and photosensitizer,In the process of synergistic catalysis,the photosensitizer reacts with the alkyl radicals generated by decarboxylation of carboxylic under visible light.The radicals act as coupling reagents with the ?-allyl palladium complex to achieve asymmetric allyl alkylation.The stereoselectivity of the reaction is completely controlled by chiral ligands.It is found that this method has wide substrate scope and potential applicability.This innovative synergistic catalytic strategy serves as the supplement of the traditional single transition metal palladium-catalyzed asymmetric allyl alkylation reaction,and has great synthetic potentialStudies towards total synthesis of sporochartine A was also conducted.