A High Yielding, One-pot Synthesis of Substituted Ureas from the Corresponding Amines Using Mitsunobu’s Reagent

Visible light-promoted synthesis of ureas and formamides from amines and CO2

A divergent visible-light-induced Ph₃P-promoted method for the synthesis of ureas and formamides from amines and CO₂ is reported. Without external additions, a range of ureas could be directly accessed under ambient temperature and pressure. Using triisopropylsilanethiol as the hydrogen source, formamides could be produced.

Synthesis of Ureas from CO2

Ureas are an important class of bioactive organic compounds in organic chemistry and exist widely in natural products, agricultural pesticides, uron herbicides, pharmaceuticals. Even though urea itself has been synthesized from CO₂ and ammonia for a long time, the selective and efficient synthesis of substituted ureas is still challenging due to the difficulty of dehydration processes. Efficient and economic fixation of CO₂ is of great importance in solving the problems of resource shortages, environmental issues, global warming, etc. During recent decades, chemists have developed different catalytic systems to synthesize ureas from CO₂ and amines. Herein, we focus on catalytic synthesis of ureas using CO₂ and amines.

Parallel synthesis of ureas and carbamates from amines and CO2 under mild conditions

A mild and efficient library synthesis technique has been developed for the synthesis of ureas and carbamates from carbamic acids derived from the DBU-catalyzed reaction of amines and gaseous carbon dioxide. Carbamic acids derived from primary amines reacted with Mitsunobu reagents to generate isocyanates in situ which were condensed with primary and secondary amines to afford the desired ureas. Similarly, carbamic acids from secondary amines reacted with alcohols activated with Mitsunobu reagents to form carbamates.