Acid-catalyzed C-O coupling of styrenes with N-hydroxyphthalimide: trapping alkenyl radicals by TEMPO

A mild metal-free acid-catalyzed 1,2-dihydroxylaminations of alkenes with N-hydroxyphthalimide and 2,2,6,6-tetramethylpiperidine N-oxyl (TEMPO) has been demonstrated under air conditions to furnish the dioxygenated products in good to excellent yields. The dioxygenated product can be easily transformed into ketone derivative using 3-chloroperbenzoic acid (m-CPBA) as the oxidant in a high yield. (C) 2016 Elsevier Ltd. All rights reserved.