초록 |
Activating CO2 using a catalyst system for producing valuable chemicals such as disubstituted urea and carbamates is of importance because it is inexpensive and abundant. However, development of a new catalyst system is very required for this purpose, especially in the case of coupling with amine-based reagent. Occasionally, adding a third reagent to the reaction system facilitates the production of target compound. Herein, a catalytic cascade reaction for generating disubstituted urea from the 3-component system, CO2, amines, and epoxides is provided. It has been found that the disubstituted urea was formed via the reaction of amines with hydroxyalkyl carbamate which has been generated from the in-situ reaction of amines with propylene carbonate that has been generated from the in-situ coupling of CO2 and epoxide during this reaction. In addition to providing a plausible reaction mechanism, the synthesis of active catalyst system and their catalytic activities depending on a various reaction parameters such as temperature, pressure, reaction time, and catalyst loading will be also presented. |