Study On Copper-catalyzed C(sp~3)-H Fluorination And Alkoxylation

Fluorine-containing compounds and oxygen-containing compounds are widely present in drug molecules and natural compounds,and therefore,the construction of C-F bond and C-O bond has always attracted the attention of synthetic chemists.As C-H fluorination and alkoxylation constitute the simplest method for preaparing these compounds,it would be highly desirable to explore new efficient means to implement these transformations under mild conditions.In this thesis,copper catalysis was employed to effect the C(sp~3)-H fluorination and alkoxylation with the help of external oxidants.This thesis is composed of three chapters.In the first chapter,recent progress made on transition metal-catalyzed C-H bond fluorination and alkoxylation is reveiwed with the literature being introduced separately according to wether it is the C(sp~2)-H bond or C(sp~3)-H bond that is functionalized.The next two chapters deal with the research conducted during the graduate study,which are summarized as follows.(1)The C(sp~3)-H fluorination was realized upon heating under copper catalysis with Et₃N·3HF as the nucleophilic fluorine source and cheap readily available potassium persulfate as the oxidant.By using Selectfluor as an oxidant,the reaction can be implemented at room temperature in much higher yield under the ligand free conditions.Both benzylic and unactivated C(sp~3)-H bond can be fluorinated with this method.(2)The alkoxylation of C(sp~3)-H bond was successfully achieved under the condition of copper(I)salt and potassium persulfate by using alcohols as nucleophiles.This protocol is suitable for etherification of tertiary alcohols as well as primary alcohols and secondary alcohols.