Adjusting the ratio of starting materials 1 and 2 resulted in a 59% yield of the trifluoromethyl-thiolated product (entry i), while dilution of the reaction mixture had a slightly positive impact on the formation of compound 4 (entry j) compared to the conditions in entry a. This phenomenon could be elucidated by the decreased likelihood of BINOL phosphate dimer formation in the diluted system, thereby preventing complexation with the cerium salt. MECHANISTIC INVESTIGATIONS To validate our mechanistic hypothesis regarding the cerium-ligand LMCT and the observed reactivity trends among different ligands in the benchmark reaction, mechanistic investigations were conducted.