Selective Synthesis of Chiral Carbocycles by Iridium-Catalyzed Asymmetric Mono-, Double-, or Triple Hydrogenation of Cyclic Dienones

A divergent N,P-iridium-catalyzed asymmetric hydrogenation of cyclic dienones into chiral cyclohexenones, cyclohexanones, or cyclohexanols is described. The π-bonds in cyclic dienones underwent hydrogenation in a sequential manner, favoring the (s)-<i>cis</i> conformed alkene followed by the olefin in the (s)-<i>trans</i> conformation and at last the ketone, to install up to three stereocenters in a single step. The simple choice of the proper catalyst allowed the formation of each respective product in high yield and stereopurity (up to 99% <i>ee</i>, up to 99/1 d.r.). This protocol provides an interesting opportunity to access multiple and stereopure carbocycles starting from the same precursor that otherwise require multistep syntheses.