Ring-Opening Metathesis Polymerization-based Recyclable Magnetic Acylation Reagents

Authors

  • Quirin M. Kainz,

    1. Institute for Organic Chemistry, University of Regensburg, Universitätsstr. 31, 93053 Regensburg (Germany), Fax: (+49)9419434121
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  • Roland Linhardt,

    1. Institute for Organic Chemistry, University of Regensburg, Universitätsstr. 31, 93053 Regensburg (Germany), Fax: (+49)9419434121
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  • Dr. Pradip K. Maity,

    1. Department of Chemistry, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, KS, 66045 (USA), Fax: (+1)7858645396
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  • Prof. Dr. Paul R. Hanson,

    Corresponding author
    1. Department of Chemistry, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, KS, 66045 (USA), Fax: (+1)7858645396
    • Department of Chemistry, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, KS, 66045 (USA), Fax: (+1)7858645396
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  • Prof. Dr. Oliver Reiser

    Corresponding author
    1. Institute for Organic Chemistry, University of Regensburg, Universitätsstr. 31, 93053 Regensburg (Germany), Fax: (+49)9419434121
    • Institute for Organic Chemistry, University of Regensburg, Universitätsstr. 31, 93053 Regensburg (Germany), Fax: (+49)9419434121
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Abstract

An operationally simple method for the acylation of amines utilizing carbon-coated metal nanoparticles as recyclable supports is reported. Highly magnetic carbon-coated cobalt (Co/C) and iron (Fe/C) nanobeads were functionalized with a norbornene tag (Nb-tag) through a “click” reaction followed by surface activation employing Grubbs-II catalyst and subsequent grafting of acylated N-hydroxysuccinimide ROMPgels (ROMP=ring-opening metathesis polymerization). The high loading (up to 2.6 mmol g−1) hybrid material was applied in the acylation of various primary and secondary amines. The products were isolated in high yields (86–99%) and excellent purities (all >95 % by NMR spectroscopy) after rapid magnetic decantation and simple evaporation of the solvents. The spent resins were successfully re-acylated by acid chlorides, anhydrides, and carboxylic acids and reused for up to five consecutive cycles without considerable loss of activity.

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