Convenient and Clean Synthesis of Isatins by Metal-Free Oxidation of OxindolesThis 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: 19 May 2017
Accepted after revision: 23 June 2017
21 July 2017 (eFirst)
A metal-free synthesis of isatins was achieved through the oxidative reactions of oxindoles with molecular oxygen in the presence of tert-butyl nitrite as an additive. This strategy provides a convenient and simple synthetic route to the construction of C=O bonds without the need for any catalyst or base. The attractive features of this reaction include its convenient procedure and mild reaction conditions.