Combining bio- and chemo-catalysis for cyclic carbonate synthesis at very low pressure: Efficient “online” utilization of CO2 obtained directly from the fermentation of sugars

A very low-pressure set-up for the synthesis of cyclic carbonates and polycarbonates from epoxides/CO2 has been constructed using our previously reported Ga-catalyst. This set-up is based on the direct use of unpurified CO2 obtained from the fermentation of sugars, which exemplifies a potentially important advancement for the future application of this widely explored CO2 utilization reaction. Using this approach, it has been possible to produce cyclic carbonates with a high bio-derived atom content when starting from bio-based epoxides, such as, eugenol oxide. Use of alternative sources of sugar beyond sucrose have also been exemplified (grapes), highlighting the potential for direct coupling to important industrial fermentation processes which emit large amounts of CO2. Finally, use of 13C6-glucose as sugar-source has allowed for the preparation of 13C-containing cyclic carbonates, with the bis-cyclic carbonates being readily converted through reaction with a diamine to form 13C-labelled polymers (13C-Non-Isocyanate PolyUrethanes; 13C-NIPU's).