Selective palladium-catalyzed direct arylation of furo[3,2-b]pyridines

Abstract

A method for palladium-catalyzed direct arylation has been developed for the selective functionalization of the C-3 and C-7 positions of 2-substituted furoACHTUNGTRENUNG[3,2-b]pyridines. An unconventional reactivity resulting from the annulation of a pyridine ring with a furan ring is outlined and results in an unprecedented C-7-H bond activation. The role of the pivalic acid additive is rationalized by invoking a concerted metallation-deprotonation pathway (CMD) for both arylations. © 2012 Wiley-VCH Verlag GmbH&Co. KGaA, Weinheim.