Camphor-Based NHC Ruthenium Catalysts in AROCM: Influence of Catalyst Structure on Enantio- and E/Z Selectivity

In this study, a new class of camphor-derived chiral NHC ruthenium complexes was designed, synthesized, and evaluated in asymmetric ring-opening cross-metathesis. Systematic modification of the ligand architecture enabled a detailed investigation of steric and electronic effects on catalytic performance.

The prepared catalyst series exhibited high activity in asymmetric ring-opening cross-metathesis (AROCM) reactions, with distinct trends observed between substituent size, catalyst reactivity, and stereoselectivity. While most complexes favored the formation of <i>E-</i>isomers, selected systems provided moderate to high enantioselectivity for <i>Z</i> products. Catechodithiolate-modified catalysts displayed a significant enhancement in <i>Z</i>-selectivity and enantioselectivity, achieving up to 99% <i>ee</i>, albeit at the expense of the catalytic activity.