Microwave-assisted halogen-bond catalyzed CO2 conversion to cyclic carbonates

Abstract

The drive to efficiently convert carbon dioxide to added-value products is a major topic in modern science with one of the utmost relevance, whether in the context of reducing the net amount of CO2 in the atmosphere with it being a greenhouse gas or to make use of it as the world’s largest C1 carbon stock. Recently, first examples have been published using halogen-bond donors as co-catalysts in the conversion of epoxides to cyclic carbonates. However, due to the use high pressure conditions and bifunctional catalysts containing both, nucleophilic halides and halogen bond (XB) donor, it is difficult to estimate the sole contribution of the latter. Herein, we have applied various XB donors as co-catalyst under initial atmospheric CO2 pressure to more accurately determine the impact of non-covalent halogen bonding on the catalytic activity. Furthermore, the reproducibility of the reaction was significantly improved by implementing microwave-assisted heating.