Mechanistic insights into nonlinear effects in copper-catalyzed asymmetric esterification

Nonlinear effects (NLEs) serve as a widespread tool in the study of asymmetric catalytic reactions. However, due to the diversity in ligand-metal coordination modes, the information obtained solely from the linear relationship between the ee values of ligands and products in complex systems is often indirect. Here, we report a precise method that directly connects the relationship between the ee values of metal complexes and products, with the purpose of determining the active species that occur in complex systems. Through an in-depth analysis of the mechanism of our previous copper-catalyzed asymmetric esterification reactions, we find an intrinsic linear relationship between the ee values of the key active metal complex (LLCu^I) and products within this traditionally non-linear system. This method holds promise as a powerful tool for the exploration of asymmetric catalysis mechanisms, heralding new avenues in the understanding and application of catalytic processes.