Construction of Pyrrolocoumarin Cores through Double C−H Annulation Cascade

Abstract

Rhodium(III)-catalyzed double C−H annulation of 3-(acetylamino)coumarins with internal arylacetylenes is reported. The reaction proceeds smoothly accompanied by two C−C and two C−N bond formation to produce 8-aryl-6H-chromeno[4’,3’:4,5]pyrrolo[2,1-a]isoquinolin-6-ones selectively. It also provides a straightforward route to natural product inspired pentacyclic pyrrolocoumarin derivatives from readily available building blocks.