| Fluorine-containing compounds play an increasing important role in the fields of agrochemicals,pharmaceuticals and materials etc,due to their special physical and chemical properties.Trifluoromethyl group is an important organic functional group containing fluorine atoms,owing to its strongelectron-withdrawing,lipophilic and the stable C-F bond,the acidic,polar,lipophilic and metabolic stability of the organic compounds will greatly changed when it was introducted into the organic molecules.Therefore,a great deal of attention has been paid to the development of new synthetic methods for the introduction of trifluoromethyl group into diverse organic derivatives.Generally,there are two methods for the construction of trifluoromethyl-containingorganic compounds.One of the strategies is using trifluoromethylating reagents such as nucleophilic,electrophilic or radical agents.The other one is the application of trifluoromethylated synthetic building blocks.Although trifluoromethylating reagents have provided direct and effective ways for the introduction of the trifluoromethyl group into organic molecules,there are some drawbacks for these reagents,such as high prices,less species and the limited application of substrate scopes.Meanwhile,the development of commercially available and stable trifluoromethylated synthetic building blocks is also meaningful.Trifluoroacetaldehyde and trifluoroketone derivatives were usually used in this process and it's vital to further expand their application in organic synthesis.The thesis consists of three parts: Chapter one: Research progress in trifluoroacetaldehyde and trifluoroketone derivatives as trifluoromethyl building blocks.The application of trifluoromethylated organic compounds in pharmaceuticals,agrochemicals,materials science and other fields were summarized in this chapter.Then we also introduced the methods for the synthesis of trifluoromethylated compounds by means of trifluoromethylating reagents and trifluoromethylated synthetic building blocks.Among them we emphasized the research progress on syntheis of trifluoromethylated compounds from trifluoroacetaldehyde and trifluoroketone derivatives.Chapter two:One-pot synthesis of trifluoromethylated homoallylic N-acylhyd razines promoted by indium powderAn one-pot reaction of trifluoroacetaldehyde methyl hemiacetal or trifluoroketones,acylhydrazines and allyl bromidepromoted by indium powder is reported,and 35 trifluoromethylated homoallylic N-acylhydrazines were obtained with good to excellent yields.The features of this process include readily availablestarting materials as trifluoromethylbuilding blocks,mild conditions and easy operation.Chapter three: Indium promoted preparation of ?-methylene-?-trifluorometh yl-?-lactams via one-pot reactionAn one-pot reaction of trifluoroacetaldehyde methyl hemiacetal or trifluoroketones,acylhydrazines and ethyl 2-(bromomethyl)acrylate promoted by indium powder has been further investigated and 22 ?-methylene-?-trifluoromethyl-?-lactams were obtained with high yieds.The features of this process include readily availablestarting materials as trifluoromethyl source,mild conditions and easy operation.The reaction provides a new method for the snythesis of trifluoromethylated ?-methylene-?-lactams. |
PDF Full Text Request