Direct Borylation of Arenes Catalyzed by γ-Fe2O3

doi:10.1055/s-0030-1257795

Synfacts 2010(8): 0959-0959
DOI: 10.1055/s-0030-1257795

Polymer-Supported Synthesis

Direct Borylation of Arenes Catalyzed by γ-Fe₂O₃

Contributor(s):Yasuhiro Uozumi, Takao Osako

G. Yan, Y. Jiang, C. Kuang*, S. Wang, H. Liu, Y. Zhang, J. Wang*
Tongji University, Shanghai and Peking University, Beijing, P. R. of China
Nano-Fe₂O₃ Catalyzed Direct Borylation of Arenes
Chem. Commun. 2010, 46: 3170-3172

Abstract

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Key words

maghemite - direct borylation - arenes - bis(pinacolato)diborane

Significance

<P>γ-Fe₂O₃ magnetic nanoparticles (particle size 58 nm) catalyzed the borylation of arenes with bis(pinacolato)diborane in the presence of di-tert-butyl peroxide and potassium carbonate under air to give the corresponding borylated products in up to 75% yield (10 examples, eq. 1). A sequential reaction via γ-Fe₂O₃-catalyzed borylation of benzene and Suzuki-Miyaura coupling with iodoarenes gave the corresponding biaryls in up to 56% yield (4 examples, eq. 2).</P>

Comment

<P>The catalytic activity of γ-Fe₂O₃ was superior to that of the other iron catalysts, such as FeCl₃, FeBr₃, FeF₃, Fe(acac)₃, Fe₂(SO₄)₃, and Fe₂O₃. In the borylation of toluene and anisole, the ortho-borylated products were obtained as major regioisomers.</P>

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