Diastereoselective synthesis of succinimide-fused polycycles intermolecular interception of indanone-allene intermediates with maleimides.

A highly diastereoselective Pd-catalyzed sequential reaction of -iodophenyl-ynones, propargylic ethers and maleimides is developed for efficient synthesis of tetracyclic succinimide derivatives containing three contiguous stereocenters and one exocyclic double bond. The reaction proceeds through Pd-catalyzed cross-coupling and propargyl Alder-ene reactions to generate a reactive indenone-allene intermediate, which undergoes an intermolecular Diels-Alder cycloaddition with maleimide to deliver a densely functionalized product. In addition, a formal four-component reaction was observed for generating polycyclic products bearing two succinimide motifs.