Copper Catalyzed And Copper Promoted Trifluoromethylation Reaction On C(sp~2) And C(sp~3)

Transition-metal catalyzed trifluoromethylation reaction have been emerged as a novel strategy for incorporation of CF3into diverse organic structures. It has becoming a research hotspot during the past decades. This thesis mainly focuses on copper catalyzed and copper promoted trifluoromethylation reaction on sp2hybrid cabon and sp3hybrid cabon, for the construction of C(sp2)-CF3bonds and C(sp3)-CF3bonds. The main contents include:Firstly, The thesis briefly reviews the history and the deveploment of the trifluoromethylation reaction in past decades. By comparing the reaction characteristics of the different metals in the introduction of a trifluoromethyl group on the carbon atom of different hybrid approach, we finally concluded that using transition-metal catalyzed trifluoromethylation reaction in organic synthesis lies in the development of efficient and gentle catalytic system for the construction of various C-CF3.In chapter3, contrary to the previously reported copper promoted trifluoromethyl reaction usually requires equivalents copper source, we first reported the copper-catalyzed trifluoromethylation of aryl boronic acids at room temperature by using Umemoto’s reagent as CF3source. The reaction is carried out at room temperature or0℃and can tolerate moisture. The reaction also shows good functional group compatibility with some unprotected OH and NH groups. This protocol provides a new method for the construction of C(sp2)-CF3bond, and enrichs the synthetic method of trifluoromethyl containing physiologically active molecules.In charper4, considering interesting challenge of developing new transition-metal-catalyzed trifluoromethylation processes to make C(sp3)-CF3bonds. we describe an unprecedented reaction for Cu-catalyzed trifluoromethylation of terminal alkenes via allylic C(sp3)-H bond activation. The reaction can be conducted under mild conditions and shows good functional group tolerance. Both experimental tests and theoretical analysis indicate that the reaction may proceed through a Heck-like four-membered-ring transition state. It presents a mechanistically uncommon example of Cu-catalyzed allylic C-H activation/functionalization.In addition, it remains a more difficult challenge to use transition metals to promote trifluoromethylation at non-activated sp3carbons. By examining a series of alkyl metal reagent and trifluoromethyl reagent, we finally found an unprecedented Cu-promoted trifluoromethylation reaction of primary and secondary alkylboronic acids with the Ruppert-Prakash reagent. It represents a general effective approach for the construction of non-activated C(sp3)-CF3bonds, and provides a rare example for Cu-promoted cross-coupling reaction of alkylboronic acids.