Get access

Structure and Dynamic Features of an Intramolecular Frustrated Lewis Pair

Authors

  • Dr. Kirill V. Axenov,

    1. Organisch-Chemisches Institut der Universität Münster, Corrensstrasse 40, 48149 Münster (Germany), Fax: (+49) 251-83-36503
    Search for more papers by this author
  • Cornelia M. Mömming,

    1. Organisch-Chemisches Institut der Universität Münster, Corrensstrasse 40, 48149 Münster (Germany), Fax: (+49) 251-83-36503
    Search for more papers by this author
  • Dr. Gerald Kehr,

    1. Organisch-Chemisches Institut der Universität Münster, Corrensstrasse 40, 48149 Münster (Germany), Fax: (+49) 251-83-36503
    Search for more papers by this author
  • Dr. Roland Fröhlich,

    1. Organisch-Chemisches Institut der Universität Münster, Corrensstrasse 40, 48149 Münster (Germany), Fax: (+49) 251-83-36503
    Search for more papers by this author
    • X-ray crystal structure analyses

  • Prof. Dr. Gerhard Erker

    Corresponding author
    1. Organisch-Chemisches Institut der Universität Münster, Corrensstrasse 40, 48149 Münster (Germany), Fax: (+49) 251-83-36503
    • Organisch-Chemisches Institut der Universität Münster, Corrensstrasse 40, 48149 Münster (Germany), Fax: (+49) 251-83-36503
    Search for more papers by this author

Abstract

Di(mesityl)cyclohexenylphosphine undergoes hydroboration with Piers' borane [HB(C6F5)2] to yield the cyclohexylene-anellated frustrated Lewis pair 5. This P/B pair splits H2 with the formation of the product 4 and adds to the C[DOUBLE BOND]O double bond of phenyl isocyanate to yield 6. In the crystal, compound 5 features a puckered four-membered heterocyclic core structure with a long P[BOND]B bond (av. 2.197(5) Å). The activation energy of the P[BOND]B cleavage of the frustrated Lewis pair 5 was determined by dynamic 19F NMR spectroscopy at ΔG(298 K)=12.1±0.3 kcal mol−1.

Ancillary