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An amphiphilic (salen)Co(III) complex is presented that accelerates the hydrolytic kinetic resolution (HKR) of epoxides almost 10 times faster than catalysts from commercially available sources. This was achieved by introducing hydrophobic chains that increase the rate of reaction in one of two ways – by enhancing cooperativity under homogeneous conditions, and increasing the interfacial area under biphasic reaction conditions. While numerous strategies have been employed to increase the efficiency of cooperative catalysts, the utilization of hydrophobic interactions is scarce. With the recent upsurge in green chemistry methods that conduct reactions ‘on water’ and at the oil‐water interface, the introduction of hydrophobic interactions has potential to become a general strategy for enhancing the catalytic efficiency of cooperative catalytic systems.

The thermal decomposition of bis (2,4,6-trichlorophenoxo)bis(pyridine)copper(II) (1) in solution does not occur spontaneously, but is induced by oxygen, or free-radical initiators. No radicals are detected until the disappearance of 1 is complete. After 1 has disappeared, phenoxy radicals slowly build up in the system to a maximum and then decay again. The disappearance of 1 is preceded by an induction period, which may be extremely long in uninitiated reactions, but this induction period is markedly diminished by free-radical initiators. The induction period is followed by a marked autoacceleration, indicative of a branched chain process. The above observations are interpreted in terms of a mechanism with the following key step: (1) fast induced decomposition of 1 by a radical to give a Cu(I) complex and a radical-substituted 2,4,6-trichlorocyclohexadienone, 3; (2) slow dissociation of 3 into the initiator radical and a 2,4,6-trichlorophenoxy radical (chain branching); (3) abstraction of a chlorine atom from 3 by Cu(I) to give CunCl and a substituted phenoxy radical. The efficient initiation of the decomposition of 1 by CC14 and CBr4 is attributed to charge transfer, or atom transfer between the carbon tetrahalide and coordinated phenoxide. Although trihalomethyl radicals efficiently abstract chlorine from 3, they do not diminish the polymer molecular weight by combining irreversibly with phenoxy radicals.

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