Studies On The Synthesis Of β-CF₃ Ketones And 1,4-Enediones By Copper Catalyzed Oxidative Reaction

Oxidative coupling is a simple,efficient and green synthetic method in organic chemistry.In recent years,oxidative coupling reaction has become a hot research topic in chemical synthesis,and is widely used in the industrial field to provide abundant intermediate resources for pharmaceuticals,agrochemicals and functional materials.Among them,the direct construction of carbon-carbon bonds（C-C）and carbon-hetero bonds（C-X）using transition metal catalyzed oxidative coupling reactions has become an important means of organic synthesis.The transition metal catalyzed oxidative coupling reaction can greatly expand the range of organic synthesis and greatly promote the development and application of organic synthesis.Organometallic chemistry has evolved over the past few decades and found that a wide variety of metal catalysts and ligands have been used in oxidative coupling reactions.Due to its rich,inexpensive,low toxicity and high catalytic efficiency,transition metal copper has attracted the attention of many organic chemists,in line with the current green and safe chemical concept.Therefore,this paper focuses on the copper catalyst,and its application in the synthesis ofβ-CF₃ ketone and1,4-enedioneone.The research work consists of the following two parts:（1）A copper/silver co-catalyzed oxidative coupling reaction between enol acetate and ICH₂CF₃ through a free radical pathway is achieved.Using enol acetate and trifluoroiodoethane as reaction substrates,copper acetate and silver sulfate as catalysts,and t-butyl hydroperoxide as oxidant and free radical initiator,a series ofβ-CF₃ ketones are synthesized.The method uses inexpensive and easily available trifluoroiodoethane as a fluorinating reagent,which greatly reduces the reaction cost and is advantageous for large-scale industrial production.In addition,control experiments show that the reaction is a free radical process,and a trifluoroethyl radical intermediate is formed during the reaction.（2）A new system for the self-coupling reaction of copper-catalyzed oxidation ofα-aminocarbonyl compounds is established for the synthesis of tetra-substituted1,4-enedione compounds.The method uses copper acetylacetonate as a catalyst,di-tert-butyl peroxide as an oxidant and triethylamine as a base to obtain various tetra-substituted 1,4-enedione compounds in high yields.The results of X-ray single crystal diffraction analysis shows that the obtained 1,4-enketone compounds are all Z-isomers,that is,the method has high stereoselectivity.