Chemoselective oxidation of aryl organoboron systems enabled by boronic acid-selective phase transfer† †Electronic supplementary information (ESI) available: Experimental procedures, assay details and spectra, characterization data for all compounds. See DOI: 10.1039/c6sc04014d Click here for additional data file.
نویسندگان
چکیده
We report the direct chemoselective Brown-type oxidation of aryl organoboron systems containing two oxidizable boron groups. Basic biphasic reaction conditions enable selective formation and phase transfer of a boronic acid trihydroxyboronate in the presence of boronic acid pinacol (BPin) esters, while avoiding speciation equilibria. Spectroscopic investigations validate a base-promoted phase-selective discrimination of organoboron species. This phenomenon is general across a broad range of organoboron compounds and can also be used to invert conventional protecting group strategies, enabling chemoselective oxidation of BMIDA species over normally more reactive BPin substrates. We also demonstrate the selective oxidation of diboronic acid systems with chemoselectivity predictable a priori. The utility of this method is exemplified through the development of a chemoselective oxidative nucleophile coupling.
منابع مشابه
Optical and electronic properties of air-stable organoboron compounds with strongly electron-accepting bis(fluoromesityl)boryl groups† †Electronic supplementary information (ESI) available: Experimental details. Additional views of the molecular structures from X-ray diffraction. Cyclic voltammograms of 2 and 3. Plots of calculated lowest energy transitions versus UV-visible absorption spectra. Variable-temperature emission and excitation spectra. Copies of all NMR spectra. Cartesian coordinates of all optimised geometries. CCDC 1010408–1010412. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c4sc02410a Click here for additional data file. Click here for additional data file.
Institut für Anorganische Chemie, Julius Hubland, 97074 Würzburg, Germany. E-ma School of Medicine, Pharmacy and Health, Stockton-on-Tees, TS17 6BH, UK Department of Chemistry, University of Tor M5S 3H6, Canada Institut für Organische Chemie, JuliusHubland, 97074 Würzburg, Germany † Electronic supplementary information Additional views of the molecular stru voltammograms of 2 and 3. Plots of ca...
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