Filling the Gaps in the Challenging Asymmetric Hydrogenation of Exocyclic Benzofused Alkenes with Ir−P,N Catalysts
Maria Biosca, Pol de la Cruz‐Sánchez, Daniel Tarr, Patricia Llanes, Erik A. Karlsson, Jèssica Margalef, Òscar Pàmies, Miquel À. Pericàs, Montserrat Diéguez
Abstract
Abstract Herein, we report a chiral phosphine‐triazole ligand for the Ir‐catalyzed asymmetric hydrogenation of exocyclic benzofused alkenes. Overcoming previous limitations, the catalytic system is able to successfully hydrogenate exocyclic olefins bearing a benzofused five‐ and six‐membered ring motif (ee's between 92 to 99%). The catalyst tolerates well the presence of several substituents and substitution patterns at both aromatic rings. The absence of a competing isomerization process together with the perfect fit of the olefins in the catalyst chiral pocket are key to surpass the previous limitations in the hydrogenation of both 5‐ and 6‐membered ring benzofused exocyclic olefins. magnified image