Rhodium(CAAC)‐Catalyzed Arene Hydrogenation of Benzo‐Fused N‐Heterocycles to Saturated Building Blocks with an all‐cis Configuration

Abstract

AbstractSaturated carbo‐ and heterocyclic building blocks can be readily obtained by the hydrogenation of aromatic carbo‐ and heterocycles. Although a variety of methods have been established to accomplish this transformation for simple arenes, the hydrogenation of aromatic N‐heterocycles is less explored. We herein report a diastereoselective arene hydrogenation which was applied to an array of benzo‐fused N‐heterocycles. A total of 48 saturated heterocycles was obtained by hydrogenation in the presence of the rhodium complex Cy(CAAC)Rh(cod)Cl in yields of 72–98% with moderate to high diastereoselectivities exhibiting the hydrogen atoms in an all‐cis arrangement. The high tolerance towards functional groups enables the formation of valuable saturated products, which offer a starting point for further derivatization.magnified image