title: Copper-catalyzed trifluoromethylation of internal olefinic C-H bonds: efficient routes to trifluoromethylated tetrasubstituted olefins and N-heterocycles.
abstract: The functionalization of internal olefins has been a challenging task in organic synthesis. Efficient CuII-catalyzed trifluoromethylation of internal olefins, that is, α-oxoketene dithioacetals, has been achieved by using Cu(OH)2 as a catalyst and TMSCF3 as a trifluoromethylating reagent. The push-pull effect from the polarized olefin substrates facilitates the internal olefinic C-H trifluoromethylation. Cyclic and acyclic dithioalkyl α-oxoketene acetals were used as the substrates and various substituents were tolerated. The internal olefinic C-H bond cleavage was not involved in the rate-determining step, and a mechanism that involves radicals is proposed based on a TEMPO-quenching experiment of the trifluoromethylation reaction. Further derivatization of the resultant CF3 olefins led to multifunctionalized tetrasubstituted CF3 olefins and trifluoromethylated N-heterocycles.
authors.forename: Zhifeng
authors.initials: Z
authors.lastname: Mao
authors.forename: Fei
authors.initials: F
authors.lastname: Huang
authors.forename: Haifeng
authors.initials: H
authors.lastname: Yu
authors.forename: Jiping
authors.initials: J
authors.lastname: Chen
authors.forename: Zhengkun
authors.initials: Z
authors.lastname: Yu
authors.forename: Zhaoqing
authors.initials: Z
authors.lastname: Xu
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D006571:Heterocyclic Compounds / Q000737:chemistry*; D006845:Hydrocarbons, Fluorinated / Q000737:chemistry*; D006860:Hydrogen Bonding; D006878:Hydroxides / Q000737:chemistry*; D008745:Methylation; D015394:Molecular Structure
chemical_list: D000475:Alkenes; D006571:Heterocyclic Compounds; D006845:Hydrocarbons, Fluorinated; D006878:Hydroxides; C001606:cupric hydroxide; D003300:Copper