Access to Piperazine-Fused Pyrrolocarbazoles Enabled by Acid-Catalyzed Stereoselective Hydroarylation of Ynamide–Indoles and Subsequent Diels–Alder Reactions/Aromatizations

Pyrrolocarbazole skeletons are well known to possess a variety of biological activities that might be therapeutically useful in the treatment of cancers. Herein, an acid-catalyzed stereoselective hydroarylation/Diels–Alder cycloaddition/aromatization of ynamide–indoles is described. We newly designed and synthesized a variety of piperazine-fused pyrrolocarbazole derivatives that could be further applied to the synthesis of potent Wee1 inhibitors.