Magnetic Nanoparticles as Inductive Heating Elements in Microreactors

doi:10.1055/s-0028-1087615

Synfacts 2009(2): 0219-0219
DOI: 10.1055/s-0028-1087615

Polymer-Supported Synthesis

Magnetic Nanoparticles as Inductive Heating Elements in Microreactors

Contributor(s):Yasuhiro Uozumi, Yoichi M. A. Yamada, Toshihiro Watanabe

S. Ceylan, C. Friese, C. Lammel, K. Mazac, A. Kirschning*
Leibniz Universität Hannover, Henkel KGaA, Düsseldorf and IFF GmbH, Ismaning, Germany
Inductive Heating for Organic Synthesis by Using Functionalized Magnetic Nanoparticles Inside Microreactors
Angew. Chem. Int. Ed. 2008, 47: 8950-8953

Abstract

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Key words

flowthrough reactor - nanoparticles - inductive heating

Significance

SiO₂-coated magnetic nanoparticles 1 and 3 (Fe₃O₄/Fe₂O₃ nanoparticles) were developed as heating elements for organic reactions, which were self-heated in an electromagnetic field. Thus, a microflow reactor (14 cm long, ø 9 mm) was filled with a mixture of magnetic nanoparticles 1 and sand (3:1, 5.5 g) without/with 400 mg of Pd-doped material 3 (2.8 mol%, 0.028 mmol Pd). The trans-esterification, Claisen rearrangement, the Buchwald-Hartwig amination, enyne metathesis and Wittig reaction were performed with 1 in an electromagnetic field under continuous-flow conditions to give the corresponding products in 75-98% yield (6 examples).

Comment

The Suzuki-Miyaura and Heck reactions were also carried out with Pd-doped magnetic nanoparticles 3 to afford the corresponding coupling products in 63-84% yield (five examples). The silica-coated Fe₃O₄/Fe₂O₃ magnetic nanoparticles 1 were prepared according to the reported procedure (M. R. Zachariah and co-workers Nanostruct. Mater. 1995, 5, 383; S. H. Ehrman et al. J. Mater. Res. 1999, 14, 4551).

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