One-pot catalytic synthesis of urea derivatives from alkyl ammonium carbamates using low concentrations of CO2

To reduce anthropogenic carbon dioxide (CO2) emissions, it is desirable to develop reactions that can efficiently convert low concentrations of CO2, present in exhaust gases and ambient air, into industrially important chemicals, without involving any expensive separation, concentration, compression, and purification processes. Here, we present an efficient method for synthesizing urea derivatives from alkyl ammonium carbamates. The carbamates can be easily obtained from low concentrations of CO2 as present in ambient air or simulated exhaust gas. Reaction of alkyl ammonium carbamates with 1,3-dimethyl-2-imidazolidinone solvent in the presence of a titanium complex catalyst inside a sealed vessel produces urea derivatives in high yields. This reaction is suitable for synthesizing ethylene urea, an industrially important chemical, as well as various cyclic and acyclic urea derivatives. Using this methodology, we also show the synthesis of urea derivatives directly from low concentration of CO2 sources in a one-pot manner. Upconverting anthropogenic CO2 into valuable chemicals generally involves separation and concentration steps of the feed gas. Here, the authors report an efficient, one-pot method for synthesizing urea derivatives from alkyl ammonium carbamates obtained from atmospheric CO2 or simulated exhaust gas with low concentrations of CO2.

Automated summary

The authors propose an efficient method for synthesizing urea derivatives from low concentrations of CO2 present in the environment, without the need for complex separation and concentration processes. This one-pot approach directly converts CO2 from exhaust gases into industrially important chemicals.