Well‐Defined Cesium Benzotriazolide as an Active Catalyst for Generating Disubstituted Ureas from Carbon Dioxide and Amines

The reaction of alkali metal carbonates with various azole compounds produced a new series of alkali metal azolides and they were applied as active catalysts for producing disubstituted ureas from the carboxylation of CO2 with various amines. Among them, cesium benzotriazolide (Cs[BTd]) was found to be most active for the carboxylation and was structurally characterized by a single-crystal X-ray diffraction. The crystal structure of highly hygroscopic Cs[BTd] was found to be [BTA]···Cs[BTd], which explains water-tolerant active species for this carboxylation reaction, leading to maximum TOF of 344 h-1 as well as high recyclability even after five successive runs.