Photothermal Synergistic Catalytic Trifluoromethylation Reaction Over Copper (?) Oxide

Transition-metal catalyzed trifluoromethylation reactions has become one of the important ways to build trifluoromethylated compounds in recent years,However,the traditional reaction,which uses the thermal catalysis as the main model,has many disadvantages,such as harsh reaction conditions,rare raw materials,complex process and does not consistent with the modern concept of green chemistry and atom economy.Recently,the photo induced or photocatalytic trifluoromethylation reactions as emerging as a green and sustainable synthesis strategy has aroused the attention in the fluorine chemistry field.Based on these,this system uses the copper oxide semiconductor as the designed core,focus on the exploration of chemical route and reaction process of trifluoromethylation reactions constructed by the visible-light induced the hole oxidation mechanism,reveals the trifluoromethylated functionalized reaction rules and influencing factors of the aromatic hydrocarbons and heterocyclic compounds in photothermal synergistic catalytic model.Through the research,the main conclusions are as follows:(1)with copper oxide as catalyst at room temperature,the visible-light(>420 nm)induced hole oxidation mechanism can successfully stimulate the oxidation of trifluoromethyl sulfinic acid sodium to create trifluoromethyl free radicals,Then the process of electrophilic substitution was used to complete the trifluoromethylated functionalization of aromatic hydrocarbons;The efficiency of photocatalytic trifluoromethylation reactions can significantly be promoted through appropriatly increasing reaction temperature(50 ?),simple dark thermal reaction(50 ?)cannot lead to trifluoromethylation reactions;At 50 ?,the main product of trifluoromethyl benzene was up to 47.26%,the total conversion of trifluoromethyl sulfinic acid sodium rate reaches 59.96%,and the reaction substrate can be successfully extended to aromatic and heterocyclic compounds(2)Based on the fact that the efficiency of the CuO catalytic photothermal synergistic trifluoromethylation reactions can significantly affect by the water content.In the vast dry reaction environment,thermal system exhibits a prominent photothermal synergy effect;The increase of water content can lead to the increase of acidity of solution system,the content of dissolved copper also increased,the newly produced copper salt is the active center of the thermal catalytic trifluoromethylation reactions;(3)The MNP radical scavenger has successfully captured trifluoromethyl free radicals,confirmed that the photo thermal synergistic catalytic trifluoromethylation reactions process exhibits typical free radicals reaction characteristics.Raman spectroscopy analysis of properties of copper oxide before and after reaction in different reaction system,the result showed that the catalyst exhibits more structural defects after photothermal reaction.With cheap and nontoxic copper oxide semiconductor as the photocatalysts,a new visible-light induced trifluoromethyl ated compounds system constructed through the photothermal synergistic catalytic model was proposed,which can be used as a reference and strategy for the fluorine chemistry under the concept of sustainable and green synthesis.