Polyfluorinated oxacalixarenes. Interaction of perfluoro- m -xylene with resorcinol and tetrafluororesorcinol

Synthesis of Polyfluorinated Thia- and Oxathiacalixarenes Based on Perfluoro-m-xylene

Perfluorinated tetrathiacalix[4]arene was obtained by heating perfluoro-m-xylene with thiourea or 2,5-difluoro-4,6-bis(trifluoromethyl)benzene-1,3-dithiol at 90 °C. Interaction of perfluoro-m-xylene with resorcinol or orcinol under mild conditions and subsequent heating of the mixture with 2,5-difluoro-4,6-bis(trifluoromethyl)benzene-1,3-dithiol leads to polyfluorinated dioxadithiacalix[4]arenes. Triphenyl and pentaphenyl ethers formed by the interaction of perfluoro-m-xylene with resorcinol under heating with thiourea gives polyfluorinated oxathiacalixarenes containing six and five aromatic nuclei, respectively.

Reactions of Bifunctional Perfluoroarylsilanes with Activated C-F Bonds in Perfluorinated Arenes

Reactions of bifunctional perfluoroarylsilanes, p- and m-C₆F₄(SiMe₃)₂ as well as o-BrC₆F₄SiMe₃, with substituted perfluoroarenes having electron-withdrawing groups were investigated using NMR and density functional theory calculation techniques. The C-F bond in perfluoroarenes was activated by the para-position of an electron-withdrawing group, such as CF₃, C₆F₅, CN, and NO₂. The reaction of C₆F₄(SiMe₃)₂ mainly occurred at the para-position of the perfluoroarenes and also occurred at the ortho-position of C₆F₅CN and C₆F₅NO₂. Two equivalent reactions of perfluoroarenes with bifunctional p- and m-C₆F₄(SiMe₃)₂ provided disubstituted perfluoroarenes, along with a small amount of protonated monosubstituted perfluoroarenes. The reaction of o-BrC₆F₄SiMe₃ with the CF₃- and CN-substituted pentafluorobenzenes provided unexpected coupling products between C-Br and C-F bonds, in addition to the coupling products between C-SiMe₃ and C-F bonds.