Janus face all-cis 1,2,4,5-tetrakis(trifluoromethyl)- and all-cis 1,2,3,4,5,6-hexakis(trifluoromethyl)- cyclohexanes

Cihang Yu, Agnes Kütt, Gerd-Volker Röschenthaler, Tomas Lebl, David B. Cordes, Alexandra M. Z. Slawin, Michael Buehl, David O'Hagan

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)

Abstract

We report the synthesis of all‐cis 1,2,4,5‐tetrakis (trifluoromethyl)‐ and all‐cis 1,2,3,4,5,6‐hexakis (trifluoromethyl)‐ cyclohexanes by direct hydrogenation of precursor tetrakis‐ or hexakis‐ (trifluoromethyl)benzenes. The resultant cyclohexanes have a stereochemistry such that all the CF3 groups are on the same face of the cyclohexyl ring. All‐cis 1,2,3,4,5,6‐hexakis(trifluoromethyl)cyclohexane is the most sterically demanding of the all‐cis hexakis substituted cyclohexanes prepared to date, with a barrier (ΔG) to ring inversion calculated at 27 kcal mol−1. The X‐ray structure of all‐cis 1,2,3,4,5,6‐hexakis(trifluoromethyl)cyclohexane displays a flattened chair conformation and the electrostatic profile of this compound reveals a large diffuse negative density on the fluorine face and a focused positive density on the hydrogen face. The electropositive hydrogen face can co‐ordinate chloride (K≈103) and to a lesser extent fluoride and iodide ions. Dehydrofluorination promoted decomposition occurs with fluoride ion acting as a base.
Original languageEnglish
Pages (from-to)19905-19909
Number of pages5
JournalAngewandte Chemie International Edition
Volume59
Issue number45
Early online date1 Sept 2020
DOIs
Publication statusPublished - 26 Oct 2020

Keywords

  • Janus face
  • Cyclohexanes
  • Trifluoromethyl groups
  • Aryl hydrogenation
  • Triaxial orientations

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