Thiol on silica as a ‘catch and release’ support for isocyanates to afford ureas
摘要:
Silica-bound thiocarbamates were prepared by Curtius rearrangement of carboxylic acids in the presence of thiol on silica gel. The solid supported thiocarbamates were found to be stable isocyanate equivalents, which upon treatment with amines efficiently afforded di- and tri-substituted ureas. The urea products released from the catch and release support were, in the majority of cases, greater than 95% pure and required no further work. (c) 2007 Elsevier Ltd. All rights reserved.
isocyanates via base-induced β-elimination of haloform N-monosubstituted trihaloacetamides is described. The rate of reaction exhibits a strong dependence on the nature of the trihalomethyl group. Thus, while the reaction of tribromoacetamides proceeds at room temperature and the reaction of trichloroacetamides requires heating in polar solvents, no reaction could be observed for any of the corresponding
A series of N-alkyl substituted urea derivatives were synthesized and evaluated for their in vitro antibacterial and antifungal activities. The N-alkyl substituted urea derivatives bearing morpholine moiety (3a–3k) showed better activities than those bearing diethylamine moiety (2a–2f). Compounds having fluoro substituent at ortho (3c) and para (3b) positions of the phenyl ring exhibited potent antimicrobial
作者:Pascal Dubé、Noah F. Fine Nathel、Michael Vetelino、Michel Couturier、Claude Larrivée Aboussafy、Simon Pichette、Matthew L. Jorgensen、Mark Hardink
DOI:10.1021/ol9023387
日期:2009.12.17
mediate the Lossenrearrangement of various hydroxamic acids to isocyanates. This process is experimentally simple and mild, with imidazole and CO2 being the sole stoichiometric byproduct. Significant for large-scale application, the method avoids the use of hazardous reagents and thus represents a green alternative to standard processing conditions for the Curtius and Hofmann rearrangements.
Efficient Direct Halogenation of Unsymmetrical N-Benzyl- and N-Phenylureas with Trihaloisocyanuric Acids
作者:Lúcia de Aguiar、Marcio de Mattos、Carlos Sanabria、Bruno Costa、Gil Viana
DOI:10.1055/s-0036-1589149
日期:2018.3
halogenation of N-phenylureas was developed using trihaloisocyanuric acids in acetonitrile at room temperature. This protocol proved to be effective for the construction of N-phenylureas with different patterns of substitution. Additionally, less reactive N-benzylureas were halogenated in the presence of a mixture of trifluoroacetic acid and acetonitrile at room temperature. A simple and efficient methodology
Environmentally benign synthesis of unsymmetrical ureas and their evaluation as potential HIV-1 protease inhibitors via a computational approach
作者:Tsenbeni N. Lotha、Kikoleho Richa、Viphrezolie Sorhie、Ketiyala、Vevosa Nakro、Imkongyanger、Vimha Ritse、Lemzila Rudithongru、Nima D. Namsa、Latonglila Jamir
DOI:10.1007/s11030-023-10615-9
日期:——
acceptable preparation of unsymmetrical ureas from thiocarbamate salts using sodium percarbonate as an oxidant. Efficacy of the unsymmetrical ureas as potential human immune deficiency virus (HIV-1) proteaseinhibitors has been evaluated via in silico approach. The results revealed interactions of the urea compounds at the active site of the enzyme with favorable binding affinities causing possible mutations
目前的工作报告了使用过碳酸钠作为氧化剂从硫代氨基甲酸盐制备不对称脲的成本效益高、产率高且环境可接受的方法。不对称脲作为潜在的人类免疫缺陷病毒 (HIV-1) 蛋白酶抑制剂的功效已通过计算机方法进行了评估。结果揭示了酶活性位点上的尿素化合物与有利的结合亲和力的相互作用,导致可能的突变阻碍酶的功能。使用已知参考文献对 IC50 进行进一步计算评估,令人满意地验证了所选化合物对 HIV-1 蛋白酶的抑制作用。除了按照环境友好的方案轻松合成尿素外,这项工作可能对持续寻找具有更好功效和降低 HIV 毒性的药物来说是一个有价值的补充。 图文摘要