Ambivalent Role of Rotamers in Cyclic(alkyl)(amino)carbene Ruthenium Complexes for Enantioselective Ring-Opening Cross-Metathesis

The development of highly efficient enantioselective olefin metathesis catalysts is a significant challenge. Using optically pure chiral cyclic (alkyl)(amino)carbene (ChiCAAC) ligands combined with preliminary mechanistic insights and density functional theory (DFT) computations, we show that catalytic performances in this field can be impaired by the formation of rotamers before the enantio-determining step. Using DFT, we also demonstrate that these results can help accelerate the process of ligand discovery by providing faster methods to discriminate potential candidates.