Degradation of N,N′-dialkyldiazenedicarboxamides with a copper(II) reagent, which was prepared from lithium 4-nitrophenoxide and copper(II) bromide in tetrahydrofuran, proceeded via formation of isocyanate to produce the corresponding 4-nitrophenyl N-alkylcarbamate with the evolution of nitrogen. Further, it was also found that 4-nitrophenyl N-alkylcarbamate reacted with primary or secondary amines
Facile direct synthesis of unsymmetrical ureas from N-Alloc-, N-Cbz-, and N-Boc-protected amines using DABAL-Me3
作者:Soosung Kang、Hee-Kwon Kim
DOI:10.1016/j.tet.2018.06.011
日期:2018.7
A practical synthetic method for the direct synthesis of unsymmetrically substituted ureas from N-Alloc-, N-Cbz-, and N-Boc-protected amines is described. In this study, efficient direct conversion of the Alloc-, Cbz-, and Boc-carbamate compounds to ureas was achieved in the presence of DABAL-Me3, an air stable and easily handled reagent. Using this reaction method, both protected aromatic and aliphatic
A Facile Method for the Preparation of Unsymmetrical Ureas Utilizing Zirconium(IV) Chloride
作者:Anna Lee、Hee-Kwon Kim、David H. Thompson
DOI:10.1002/bkcs.10646
日期:2016.2
ureas from amines is described. Carbamoyl imidazole compounds were prepared by the reaction of 1,1‐carbonyldiimidazole with primary or secondary amines, and further activation by treatment with zirconium(IV) chloride to generate the desired urea. This reaction protocol was applied to the synthesis of tri and tetrasubstituted ureas with high yields. This study provides an alternative guideline for the
Biocompatible ligation of isonitriles and amines to ureas in neutral aqueous medium was developed here. Direct labeling of Ac4GlcN has been achieved in Hep G2 cells, which may be used to diagnose proteins with abnormal expression in their native habitats. The ligation will provide new avenues for amines and isonitriles in chemical biology applications.
这里开发了在中性水介质中异腈和胺与脲的生物相容性连接。Ac 4 GlcN 的直接标记已在 Hep G2 细胞中实现,可用于诊断在其天然栖息地中表达异常的蛋白质。该连接将为胺和异腈在化学生物学应用中提供新途径。
Novel Direct Synthesis of Asymmetrical Urea Compounds from Trichloroethyl Carbamates Using Catalytic DBU