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DOI: 10.1055/s-0030-1257795
Direct Borylation of Arenes Catalyzed by γ-Fe2O3
Contributor(s):Yasuhiro Uozumi, Takao OsakoTongji University, Shanghai and Peking University, Beijing, P. R. of China
Nano-Fe2O3 Catalyzed Direct Borylation of Arenes
Chem. Commun. 2010, 46: 3170-3172
Publication History
Publication Date:
22 July 2010 (online)
Key words
maghemite - direct borylation - arenes - bis(pinacolato)diborane
Significance
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).
Comment
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.