Synthesis of Indoline-2,3-diones by Radical Coupling of Indolin-2-ones with tert-Butyl HydroperoxideThis research is sponsored by research funds of NBU (No. ZX2016000706), the foundation of Ningbo University (No. XYL17009), and the K. C. Wong Magna Fund in Ningbo University.
Received: 23 July 2017
Accepted after revision: 22 August 2017
14 September 2017 (eFirst)
◊ These authors contributed equally to this work.
A novel strategy has been developed for the synthesis of indoline-2,3-diones through a metal-free radical-coupling reaction. Alkyl radicals derived from indolin-2-ones through a radical-transfer reaction combine with the tert-butylhydroperoxy radical readily generated from commercially available tert-butyl hydroperoxide to afford 3-(tert-butylperoxy)indolin-2-one intermediates that can be further transformed into indoline-2,3-diones under air. This strategy provides a simple and eﬃcient route to the construction of a C=O bond without the use of any metal catalyst or base.