95461-01-1Relevant articles and documents
N -Acylbenzotriazoles as Proficient Substrates for an Easy Access to Ureas, Acylureas, Carbamates, and Thiocarbamates via Curtius Rearrangement Using Diphenylphosphoryl Azide (DPPA) as Azide Donor
Yadav, Mangal S.,Singh, Sumt K.,Agrahari, Anand K.,Singh, Anoop S.,Tiwari, Vinod K.
, p. 2494 - 2502 (2021/03/26)
A diverse range of ureas, N -acylureas, carbamates, and thiocarbamates has been synthesized in good to excellent yields by reacting N -acylbenzotriazoles individually with amines or amides or phenols or thiols in the presence of diphenylphosphoryl azide (DPPA) as a suitable azide donor in anhydrous toluene at 110 °C for 3-4 hours. In this route, DPPA was found to be a good alternative to trimethylsilyl azide and sodium azide for the azide donor in Curtius degradation. The high reaction yields, one-pot and metal-free conditions, straightforward nature, easy handling, use of readily available reagents, and in many cases avoidance of column chromatography are the notable features of the devised protocol.
Palladium-catalyzed N -acylation of monosubstituted ureas using near-stoichiometric carbon monoxide
Bjerglund, Klaus,Lindhardt, Anders T.,Skrydstrup, Troels
experimental part, p. 3793 - 3799 (2012/06/04)
The palladium-catalyzed carbonylation of urea derivatives with aryl iodides and bromides afforded N-benzoyl ureas (20 examples) in yields attaining quantitative via the application of near-stoichiometric amounts of carbon monoxide generated from the decarbonylation of the CO precursor, 9-methylfluorene-9-carbonyl chloride. The synthetic protocol displayed good functional group tolerance. The methodology is also highly suitable for 13C isotope labeling, which was demonstrated through the synthesis of three benzoyl ureas, including the insecticide triflumuron, whereby 13CO was incorporated into the core structure.
