Visible-light-induced oxidative ring expansion of indoles with amidines

Abstract

An efficient and mild visible-light-enabled reaction involving the oxidative ring expansion of indoles with amidines in the aqueous phase at room temperature is developed. Benzo[1,3,5]triazocin-6(5H)-ones and quinazolinones were facilely obtained as the terminal products by using 2-substituted indoles and substituent-free indoles as substrates, respectively. This protocol features mild conditions, excellent functional group tolerance, and moderate to good yields.