Copper-Catalyzed Oxidative Dimerization of 2-Oxindoles under Base-Free Conditions

^◊ These authors contributed equally to this work

Abstract

A practical copper-catalyzed oxidative dimerization of 2-oxindoles using di-tert-butyl peroxide as the radical initiator under base-free conditions was achieved, which not only provided an efficient route to prepare various 3,3′-bioxindoles, but also represented a simple strategy for C(sp³)–H functionalization/C–C bond formation. A radical mechanism was proposed based on the reaction results and controlling experiments.

Key words

base-free - copper - oxidative dimerization - 2-oxindoles

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