Abstract
Catalytic hydrogenation of CO(2)-derived urea derivatives or carbamates provides an indirect and efficient solution for the chemical transformation of CO(2) under mild conditions, avoiding the high temperatures and pressure required for direct catalysis to overcome the thermodynamic energy barrier and the low yield of the targeted product. However, the reported catalyst systems focus mainly on the preparation of one specific product, and switching the product type requires external acid/base additives, which limits the development of this protocol. Here, we report a promising route for the hierarchical reduction of CO(2)-derived urea derivatives or carbamates using an Ir-based PNP pincer catalyst system, enabling the selective production of specific chemicals (methanol, formamides, N-methylamines, or N,N-dimethylamines) for the first time by altering reaction conditions, especially the reaction temperature. This work demonstrates the significant potential of hydrogenation of urea derivatives or carbamates for the indirect conversion of CO(2) to valuable chemicals and fuels, providing a facile temperature-dependent product-switching strategy in one catalytic system.