Palladium-catalyzed hydrofunctionalization cyclization of 1,3-enynes to access cyclopenta[b]indoles

Abstract

We herein present a palladium-catalyzed sequential hydroarylation and hydroalkylation of readily available 1,3-enynes with indole-2-malonates. This redox-neutral strategy provides a facile, atom and step-economical route for the synthesis of cyclopenta[b]indoles under mild conditions, featuring good yields, excellent chemo- and regioselectivities and broad substrate tolerance as well. The synthetic utility of this method is further highlighted by the gram-scale preparation and rapid access to diverse value-added indole derivatives.