Selective nickel-catalyzed dehydrogenative-decarboxylative formylation of indoles with glyoxylic acid

Herein we present a new strategy for the dehydrogenative-decarboxylative coupling of indoles with glyoxylic acid. A broad range of indoles were transformed into the corresponding 3-formylindoles in moderate to good yields and excellent functional group tolerance. Notably, no N-formylation product was detected under our conditions.