Unexpected phenol production from arylboronic acids under palladium-free conditions; organocatalyzed air oxidation.
An intriguing class of quinones that efficiently catalyze the air oxidation (overall hydroxylation) of arylboronic acids to the corresponding phenol is reported. Autocatalysis in the parent system is particularly efficient and leads to rapid, quantitative synthesis of quinones such as 4 from boronic acid 1 at room temperature using air as stoichiometric oxidant. The efficiency results from a balance between two-stage conjugate addition and migration with each step driven by aromatization of a naphthalene fragment.
School of Chemistry, University of East Anglia , Norwich NR4 7TJ, UK.
Andrew N
AN
Cammidge
Victoria H M
VH
Goddard
Christopher P J
CP
Schubert
Hemant
H
Gopee
David L
DL
Hughes
Daniel
D
Gonzalez-Lucas