Asymmetric Counteranion-Directed Halogen Bonding Catalysis
Dominik L. Reinhard, Anna Iniutina, Sven Reese, T. Shaw, Christian Merten, Benjamin List, Stefan M. Huber
Abstract
High Resolution Image Download MS PowerPoint Slide Halogen bonding has been established as a promising tool in organocatalysis. Asymmetric processes are nevertheless scarce, and their applications are limited to a few studies applying chiral halogen bond donors. Herein, we combine halogen bonding with asymmetric counteranion-directed catalysis, providing the first highly enantioselective example of such an approach. A strong bidentate iodine(III)-based catalyst with chiral disulfonimides as counteranions is applied in the first asymmetric organocatalysis of the Diels–Alder reaction between cyclopentadiene and trans -β-nitrostyrene, the key step in the synthesis of the drug fencamfamine, which was prepared with high enantioselectivity.