TEMPO Supported on Magnetic C/Co-Nanoparticles: A Highly Active and Recyclable Organocatalyst

Authors

  • Alexander Schätz Dipl.-Chem.,

    1. Institut für Organische Chemie, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg (Germany), Fax: (+49) 941-943-4121
    Search for more papers by this author
  • Robert N. Grass Dr.,

    1. Institut für Chemie- und Bioingenieurwissenschaften, Department Chemie und Angewandte Biowissenschaften, ETH Zürich, Wolfgang-Pauli-Strasse 10, 8093 Zürich (Switzerland), Fax: (+41) 44-633-1083
    Search for more papers by this author
  • Wendelin J. Stark Prof.,

    1. Institut für Chemie- und Bioingenieurwissenschaften, Department Chemie und Angewandte Biowissenschaften, ETH Zürich, Wolfgang-Pauli-Strasse 10, 8093 Zürich (Switzerland), Fax: (+41) 44-633-1083
    Search for more papers by this author
  • Oliver Reiser Prof. Dr.

    1. Institut für Organische Chemie, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg (Germany), Fax: (+49) 941-943-4121
    Search for more papers by this author

Abstract

TEMPO was grafted on graphene-coated nanobeads with a magnetic cobalt core by using a general applicable “click”-chemistry protocol. The new heterogeneous CoNP–TEMPO emerged as a highly active catalyst for the chemoselective oxidation of primary and secondary alcohols using bleach as terminal oxidant. The outstanding stability of the C/Co nanoparticles enables the nanopowder to tolerate several TEMPO-mediated iterative oxidation reactions without any significant loss in catalyst activity. Furthermore, the excellent magnetic properties enable the rapid separation and quantitative recycling of CoNP–TEMPO out of the reaction mixture by simple magnetic decantation. The recovered nanoparticles can be subsequently reused without any further purification.

Ancillary