Chemoselective oxidation of aryl organoboron systems enabled by boronic acid-selective phase transfer. Issue 2 (8th November 2016)

• Record Type: Journal Article
• Authors: Molloy, John J.; Clohessy, Thomas A.; Irving, Craig; Anderson, Niall A.; Lloyd-Jones, Guy C.; Watson, Allan J. B.
• Is Part Of: Chemical science. Volume 8:Issue 2(2017)
• Page Start: 1551
• Page End: 1559
• Publication Date: 2016-11-08
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c6sc04014d
• Languages: English
• ISSNs: 2041-6520

Abstract

Abstract : Chemoselective boronate formation and phase transfer allows chemoselective Brown oxidation of boronic acids in the presence of boronic esters. Abstract : 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.