Synthesis and structure of all-syn-1,2,3,4-tetrafluorocyclohexane

Abstract

Preparation of the all-syn isomer of 1,2,3,4-tetrafluorocyclohexane is reported; X-ray structural studies shows a conformation with two of the C-F bonds oriented 1,3-diaxial to each other and (19)F-NMR reveals a through space diaxial (4)J(FF) coupling constant of 29 Hz.

The Synthesis of η‐1,2,3,4,5,6‐Hexafluorocyclohexane (Benzene Hexafluoride) from Benzene

“…[14,15] This analysis reveals that the two 1,3-diaxial C À F bonds show a large through-space coupling ( 4 J HF = 30.6 Hz) confirming their close proximity in space. Through-space F···F couplings of this magnitude are rarely observed except in rigid molecular systems, [16] although they have been observed recently in the structurally related all-syn 1,2,3,4-tetrafluorinated cyclohexane [15] and a difluorinated hexose. Through-space F···F couplings of this magnitude are rarely observed except in rigid molecular systems, [16] although they have been observed recently in the structurally related all-syn 1,2,3,4-tetrafluorinated cyclohexane [15] and a difluorinated hexose.…”

Janus all‐cis‐1,2,3,4,5,6‐Hexafluorocyclohexane: A Molecular Motif for Aggregation‐Induced Enhanced Polarization

“…Apart from acyclic hydrocarbon‐based systems, O'Hagan, et al. and others have synthesized a few of the fluorocyclohexane molecules with one to six F atoms substituted in the chair conformation of cyclohexane . The chair form of 1,2,3,4,5,6‐hexafluorocyclohexane ( 1 , Scheme ) can possess nine unique configurational and 15 possible conformational isomers.…”

Synthesis of selectively fluorinated cyclohexanes: The observation of phenonium rearrangements during deoxyfluorination reactions on cyclohexane rings with a vicinal phenyl substituent

“…We have recently introduced all-cis phenyl-2,3,5,6-tetrafluorocyclohexane 1 as the starting point for the synthesis of a diversity of products 2 carrying a tetrafluorocyclohexyl motif with four fluorine up [1][2][3][4][5][6]. The diversity emerges as the aromatic ring of 1 can be modified by a range of standard electrophilic aromatic substitution reactions [4,6].…”

“…This was further supported by a deuterium isotope labelling experiment. [1,5] As part of a programme to extend the structural diversity of the all-cis tetrafluorocyclohexane motifs 2 we were interested in placing a methyl group at the benzylic position to generate products such as 12. To that end we started with the well known modification of the Birch reduction of biphenyl 1 which involves in situ methylation to generate diene 13 [7,9].…”