Investigation On The C-F Bonds Activation Reactions Of (Trifluoromethyl)Alkenes

Organofluorine compounds play an increasingly important role in many fields of chemistry and daily life.Fluorine atom endows some special products,such as polytetrafluoroethylene（PTFE）,freon,fluorine liquid crystal,optical fiber,medicine and pesticide,with unique properties,providing significant benefits for human production and life.In order to meet the inceasingly urgent demand for fluorinated compounds,it is very important to develop new methods and strategies to construct these high-value molecules.In recent years,the activation reactions of C-F bonds,such as the activation of C（sp²）-F bonds,have been widely concerned and studied.However,the activation reactions of C（sp³）-F bonds in the trifluoromethyl group is still underdeveloped..The high bond dissociation energy and polarity of C（sp³）-F bonds as well as the shielding effect of three fluorine atoms in the trifluoromethyl group make this C（sp³）-F bond activation subject become a great challenge.（Trifluoromethyl）alkenes are readily available substrates that have been successfully utilized in the transformations of C（sp³）-F bonds activation in a CF₃ group.However,these reactions also have some disadvantages,such as limited reaction substrates,single reaction sites and pathways.Therefore,the development of novel C（sp³）-F bond activation reactions of（trifluoromethyl）alkenes has significant theoretical and practical application value.In this context,this paper is committed to the development of novel defluorinative reactions of（trifluoromethyl）alkenes for the construction of fluorinated compounds.These reactions feature simple and mild conditions,transition-metal-free,and wide scope of substrates.The details are summarized as follows:In Chapter 2,we reported a novel ipso-defluorooxylation of（trifluoromethyl）alkenes with oximes to provide various O-（1,1-difluoroallyl）oxime ethers in high yields.This represents the first ipso-defluorinative functionalization reaction of（trifluoromethyl）alkenes.Preliminary mechanism studies indicated that the reaction underwent the S_N2-type substitution pathway.In Chapter 3,the 1,3-diaminations of（trifluoromethyl）alkenes with indoles,pyrroles,carbazoles,and sulfonamides were developed.These reactions were triggered by ipso-defluorinative amination of（trifluoromethyl）alkenes,and attractive dimers with a monofluoroalkene moiety containing a linker were synthesized in high yields with good to excellent Z/E selectivities.The reaction could be carried out in gram scale.