Using computational chemistry as a tool, Wang’s group has designed metal-free hydrogenation catalysts. The implementation includes designing proper electronic structure to split H
2 and building appropriate chemical scaffold to prevent possible side reactions which may deactivate the catalysts. Interestingly, the designed catalysts bear resemblances to the well-known metal-ligand bifunctional hydrogenation catalysts in terms of both the activation principle and the hydrogenation mechanisms. The hydrogenations catalyzed by the designed catalysts proceed via two major steps, hydrogen activation and hydrogen transfer. The predicted energetics for completing the catalytic cycles indicates these reactions have feasible kinetics and thermodynamics for experimental realizations under ambient conditions. We also showed how to improve the catalysis by using the “cooperative effect” and the nonbonding interactions. The reported catalysts can be the targets for experimental synthesis. The strategy can be borrowed to design similar catalysts.
The related results were published by Dalton Transactions as cover paper (Dalton Trans. 2010, 39, 4038-4047.). “This is a very good computational study in which the authors develop a strategy to design catalysts for hydrogenation of imines. The molecules investigated are masterly designed and computationally tested and are closely related to the requirements of the industry. The authors know well the topic of molecules with "frustrated Lewis pairs". The research has been nicely presented and an accurate methodology has been used. Care has been taken in particular theoretical aspects such as the consideration of the entropic effects. The manuscript can be published in its present form.” one of the reviewers made such comments on this work.
