Exploiting Decarbonylation and Dehydrogenation of Forma-mides for the Synthesis of Ureas, Polyureas, and Poly(urea-urethanes)

Urea derivatives, polyureas, and poly(urea-urethanes) are materials of great interest. However, their current methods of syn-thesis involve toxic feedstock - isocyanate and phosgene gas. There is a significant interest in developing alternative meth-odologies for their synthesis from safer feedstock. We report here new methods for the synthesis of urea derivatives, polyure-as, and polyurea(urethane) using a ruthenium pincer catalyst. In this approach, urea derivatives and polyureas are synthesized from the self-coupling of formamides and diformamides, respectively, whereas polyurea(urethanes) are synthesized from the coupling of diformamides and diols. CO and H2 gases are eliminated in all these processes. Decarbonylation of formamides using such organometallic catalysts has not been reported before and therefore mechanistic insights have been provided using experiments and DFT computation to shed light on pathways of these processes.