US EPA

7445682 

Journal Article 

Alkali Metal Salt as Catalyst for Direct Synthesis of Carbamate from Carbon Dioxide 

Zhang, Q; Yuan, H; Fukaya, N; Choi, J 

2018 

ACS Sustainable Chemistry & Engineering
ISSN: 2168-0485 

American Chemical Society 

6 

5 

6675-6681 

English 

10.1021/acssuschemeng.8b00449 

WOS:000431927500108 

Carbamates are an important motif in agricultural chemistry, medicinal chemistry, and polyurethane preparation. Potassium carbonate (K2CO3) is a common, nontoxic, and inexpensive chemical and is widely used in organic synthesis. Herein we report the use of K2CO3 as a catalyst for direct synthesis of carbamate from amine, silicate ester, and carbon dioxide. Especially, both alkyl amines and aromatic amines could be activated, largely expanding the substrate scope compared with the use of alcohol as the coupling reagent. Anion-assisted deprotonation of amine was the key step in the catalytic process, and the alkali metal served as a Lewis acid. Isolated yield of the corresponding carbamate was up to 97%. The use of K2CO3 as the catalyst decreased 49 kJ mol-1 activation energy of the reaction compared with our previously reported ionic liquid catalyst from Arrhenius analyses. © 2018 American Chemical Society. 

Carbon dioxide transformation; Homogeneous catalysis; Carbamate; Alkali metal; Silicate ester; C1 building block