A Facile Route to Flavone-3-Carboxamides and Flavone-3-Carboxylates via Palladium-Catalyzed Amino- and Aryloxy-Carbonylation Reactions.

A library of C-3 functionalized flavones was successfully provided via palladium-catalyzed amino- and aryloxycarbonylation reactions of 3-iodoflavone (), under mild conditions. This methodology showed good functional group tolerance using a variety of amines and phenols, under an atmospheric pressure of carbon monoxide as a carbonyl source. While the flavone-3-carboxamides () were produced in 22-79%, the flavone-3-carboxylates () were obtained in excellent yields (up to 88%), under identical reaction conditions, just by switching -nucleophiles to -nucleophiles. The convenient availability of the involved starting materials confers simplicity to this approach to design new C-3-substituted flavones of biological relevance. The solid-state structures of flavone-3-carboxamide () and flavone-3-ester () were further studied by single-crystal XRD analysis.