Scope and Mechanism of a True Organocatalytic Beckmann Rearrangement with a Boronic Acid/Perfluoropinacol System under Ambient Conditions
Xiaobin Mo, Timothy D. R. Morgan, Hwee Ting Ang and Dennis G. Hall*
*Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada, Email: dennis.hallualberta.ca
X. Mo, T. D. R. Morgan, H. T. Ang, D. G. Hall, J. Am. Chem. Soc., 2018, 140, 5264-5271.
2-Alkoxycarbonyl- and 2-phenoxycarbonyl-phenylboronic acid are efficient catalysts for the direct and chemoselective activation of oxime N-OH bonds in the Beckmann rearrangement. Using only 5 mol % of boronic acid catalyst and perfluoropinacol as an additive in a polar solvent mixture, the operationally simple protocol features mild conditions, a broad substrate scope, and a high functional group tolerance.
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Beckmann Rearrangement, Organocatalysis