Abstract
A series of novel bis‐urea‐functionalized (salen)Co complexes has been developed. The complexes were designed to form self‐assembled structures in solution through intermolecular urea–urea hydrogen‐bonding interactions. These bis‐urea (salen)Co catalysts resulted in rate acceleration (up to 13 times) in the hydrolytic kinetic resolution (HKR) of rac‐epichlorohydrin in THF by facilitating cooperative activation, compared to the monomeric catalyst. In addition, one of the bis‐urea (salen)Co^III^ catalyst efficiently resolves various terminal epoxides even under solvent‐free conditions by requiring much shorter reaction time at low catalyst loading (0.03–0.05 mol %). A series of kinetic/mechanistic studies demonstrated that the self‐association of two (salen)Co units through urea–urea hydrogen bonds was responsible for the observed rate acceleration. The self‐assembly study with the bis‐urea (salen)Co by FTIR spectroscopy and with the corresponding (salen)Ni complex by ^1^H NMR spectroscopy showed that intermolecular hydrogen‐bonding interactions exist between the bis‐urea scaffolds in THF. This result demonstrates that self‐assembly approach by using non‐covalent interactions can be an alternative and useful strategy toward the efficient HKR catalysis.