Isocyanate-Free Polyurea Synthesis via Ru-Catalyzed Carbene Insertion into the N-H Bonds of Urea.
Macromolecules
; 55(21): 9690-9696, 2022 Nov 08.
Article
em En
| MEDLINE
| ID: mdl-36397938
ABSTRACT
Polyureas have widespread applications due to their unique material properties. Because of the toxicity of isocyanates, sustainable isocyanate-free routes to prepare polyureas are a field of active research. Current routes to isocyanate-free polyureas focus on constructing the urea moiety in the final polymerizing step. In this study we present a new isocyanate-free method to produce polyureas by Ru-catalyzed carbene insertion into the N-H bonds of urea itself in combination with a series of bis-diazo compounds as carbene precursors. The mechanism was investigated by kinetics and DFT studies, revealing the rate-determining step to be nucleophilic attack on a Ru-carbene moiety by urea. This study paves the way to use transition-metal-catalyzed reactions in alternative routes to polyureas.
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Base de dados:
MEDLINE
Idioma:
En
Revista:
Macromolecules
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
Holanda