Aryl-O reductive elimination from reaction of well-defined aryl-Cu-III species with phenolates: the importance of ligand reactivity

Well-defined aryl-Cu-III species undergo rapid reductive elimination upon reaction with phenolates (PhO-), to form aryl-OPh cross-coupling products. Kinetic studies show that the reaction follows a different mechanistic pathway compared to the reaction with phenols. The pH active cyclized pincer-like ligand undergoes an initial amine deprotonation that triggers a faster reactivity at room temperature. A mechanistic proposal for the enhanced reactivity and the role of EPR-detected Cu-II species will be discussed in detail.