Asymmetric construction of enantioenriched furo[2,3-b]pyridines through sequential gold, palladium/phosphoric acid catalysis

Abstract

Presented herein is a multi-catalytic protocol, involving gold, palladium and phosphoric acid, which enables a relay cycloisomerisation/asymmetric [4 + 2] cycloaddition process between ynamides and carbonate of 4-hydroxy-2-cyclopentenone. Diverse furo[2,3-b]pyridine derivatives were straightforwardly constructed in a one-pot fashion with uniformly good to excellent yields and diastereo and enantioselectivities, and they can be further converted to complex heterocycles after simple derivations.