Chiral Atropisomeric‐NHC Catechodithiolate Ruthenium Complexes for Z‐Selective Asymmetric Ring‐Opening Cross Metathesis of Exo‐Norbornenes

Abstract A set of 16 chiral ruthenium complexes containing atropisomerically stable N‐Heterocyclic Carbene (NHC) ligands was synthesized from prochiral NHC precursors. After a rapid screening in asymmetric ring‐opening‐cross metathesis (AROCM), the most effective chiral atrop BIAN‐NHC Ru‐catalyst (up to 97 : 3 er) was then converted to a Z ‐selective catechodithiolate complex. The latter proved to be highly efficient in Z ‐selective AROCM of exo ‐norbornenes affording valuable trans ‐cyclopentanes with excellent Z ‐selectivity (>98 %) and high enantioselectivity (up to 96.5 : 3.5 er).