14370-47-9Relevant academic research and scientific papers
SYNTHESIS OF ALIPHATIC ISOCYANATES VIA A TWO-PHASE HOFMANN REACTION
Sy, Anita O.,Raksis, Joseph W.
, p. 2223 - 2226 (1980)
A convenient method of preparing aliphatic isocyanates via a two-phase Hofmann reaction using a phase transfer catalyst is described.
Synthesis and Properties of 1,3-Disubstituted Ureas and Their Isosteric Analogs Containing Polycyclic Fragments: V. 1-(Bicyclo[2.2.1]heptan-2-yl)-3-R- and 1-(1,7,7-Tricyclo[2.2.1]heptan-2-yl)-3-R-ureas
Pitushkin,Burmistrov,Saeef, M. H. Abbas,Vernigora,Butov
, p. 1893 - 1904 (2021/01/12)
Abstract: A series of 1,3-disubstituted ureas containing a bicyclic lipophilic group ofnatural origin were synthesized by the reactions of bicyclo[2.2.1]heptane-2-ylisocyanate with amines in yields of up to 82% and by the reactions ofbicyclo[2.2.1]heptan-2-amine and 1,7,7-trimethylbicyclo[2.2.1]heptan-2-aminewith 1,1'-carbonyldiimidazole in yields of up to 94%. The synthesized ureas arepotent inhibitors of RNA virus replication and soluble epoxide hydrolase.
Alkyl Isocyanates via Manganese-Catalyzed C-H Activation for the Preparation of Substituted Ureas
Huang, Xiongyi,Zhuang, Thompson,Kates, Patrick A.,Gao, Hongxin,Chen, Xinyi,Groves, John T.
supporting information, p. 15407 - 15413 (2017/11/06)
Organic isocyanates are versatile intermediates that provide access to a wide range of functionalities. In this work, we have developed the first synthetic method for preparing aliphatic isocyanates via direct C-H activation. This method proceeds efficiently at room temperature and can be applied to functionalize secondary, tertiary, and benzylic C-H bonds with good yields and functional group compatibility. Moreover, the isocyanate products can be readily converted to substituted ureas without isolation, demonstrating the synthetic potential of the method. To study the reaction mechanism, we have synthesized and characterized a rare MnIV-NCO intermediate and demonstrated its ability to transfer the isocyanate moiety to alkyl radicals. Using EPR spectroscopy, we have directly observed a MnIV intermediate under catalytic conditions. Isocyanation of celestolide with a chiral manganese salen catalyst followed by trapping with aniline afforded the urea product in 51% enantiomeric excess. This represents the only example of an asymmetric synthesis of an organic urea via C-H activation. When combined with our DFT calculations, these results clearly demonstrate that the C-NCO bond was formed through capture of a substrate radical by a MnIV-NCO intermediate.
