Lithium-promoted hydrogenation of carbon dioxide to formates by heterobimetallic hydridozinc alkoxide clusters.

The remarkably distinct reactivity of hydridozinc heterobimetallic cubanes [(HZnOtBu)4-n(thf LiOtBu)n] 1a-1d towards CO2 is reported--the hydride transfer from Zn-H to CO2 is drastically accelerated in the presence of Li ions in 1b-1d which led to the respective metal formate hydrates; the systems are inspiring models for the selective conversion of water gas into formates on lithium-promoted ZnO supports.