Transition‐Metal‐Free Catalyzed Dearomatizative Esterification of Indole

Abstract

3,3‐Disubstituted oxindoles are important intermediates and building blocks in organic synthesis. Herein, a domino procedure for the synthesis of various 3,3‐disubstituted oxindole from indoles has been developed. Without transition metal catalyst, indoles were selectivity dearomatized in an efficient manner without any halogen additives.

Copper-Catalyzed Oxidative Dearomatized Oxyalkylation of Indoles with Alcohols: Synthesis of 3-Alkoxy-2-Oxindoles

“…Sun, Hong, Wang, and co-workers, described an oxidation and intramolecular lactonization of indolepropionic acids, and NaI as the catalyst and H 2 O 2 as the oxidant were used (3, Scheme ). To the best of our knowledge, the intermolecular oxidative dearomatized functionalization of indoles was rare; more importantly, the directly dearomatized functionalization of indoles allows a step-economic synthetic approach to functionalized oxindoles …”