58490-95-2Relevant academic research and scientific papers
Benzylic C-H isocyanation/amine coupling sequence enabling high-throughput synthesis of pharmaceutically relevant ureas
Krska, Shane W.,Lin, Shishi,Nkulu, Leah E.,Stahl, Shannon S.,Suh, Sung-Eun
, p. 10380 - 10387 (2021/08/12)
C(sp3)-H functionalization methods provide an ideal synthetic platform for medicinal chemistry; however, such methods are often constrained by practical limitations. The present study outlines a C(sp3)-H isocyanation protocol that enables the synthesis of diverse, pharmaceutically relevant benzylic ureas in high-throughput format. The operationally simple C-H isocyanation method shows high site selectivity and good functional group tolerance, and uses commercially available catalyst components and reagents [CuOAc, 2,2′-bis(oxazoline) ligand, (trimethylsilyl)isocyanate, andN-fluorobenzenesulfonimide]. The isocyanate products may be used without isolation or purification in a subsequent coupling step with primary and secondary amines to afford hundreds of diverse ureas. These results provide a template for implementation of C-H functionalization/cross-coupling in drug discovery.
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.
Compositions and method of using ureidotetralin compounds or derivatives thereof
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, (2008/06/13)
This invention relates to a method for enhancing the growth rate of animals, particularly farm animals such as livestock, by administering to said animals compositions containing a growth-enhancing amount of a ureidotetralin compound or derivative thereof.
