Silver-Catalyzed Intramolecular C-2 Selective Acylation of Indoles with Aldehydes: An Atom-Economical Entry to Indole-Indolone Scaffolds

A direct annulation reaction of N-(2-formylaryl)indoles has been developed, which can provide a new entry to biologically and medicinally important indole-indolone scaffolds via a silver-catalyzed direct oxidative coupling between aldehyde CH and sp(2) CH bonds for the first time. Remarkably, this strategy displayed excellent functional group compatibilities, thereby suggesting its wide potential for applications in developing and synthesizing new drug-like compounds containing indole-indolone frameworks.