我们报告了一种新的电化学无负载电解质方法,用于通过草酸氧化合成尿素、氨基甲酸酯和硫代氨基甲酸酯。这种简单、实用且无光气的路线包括在有机碱存在下通过草酸的阳极脱羧原位生成异氰酸酯中间体,然后一锅加入合适的亲核试剂以提供相应的尿素,氨基甲酸酯和硫代氨基甲酸酯。此程序适用于不同的胺、醇和硫醇。此外,当使用单程连续电化学流动条件并且该反应在碳石墨 C gr /C gr 在流动池中,可以在 6 分钟的停留时间内以高产率获得尿素化合物,解锁在批量条件下无法访问的底物,同时易于扩展。
Chemoselective isocyanide insertion into the N–H bond using iodine–DMSO: metal-free access to substituted ureas
作者:Porag Bora、Ghanashyam Bez
DOI:10.1039/c8cc05019h
日期:——
Insertion of isocyanides into the N–H bond gives access to many medicinally important and structurally diverse complex nitrogen-containing heterocycles. Although the transition metal catalyzed isocyanideinsertion into the N–H bond is very common, polymerization of isocyanides in the presence of a transition metal and their strong coordination with metals are the common drawbacks. On the other hand
Highly Efficient Synthesis of Ureas and Carbamates from Amides by Iodosylbenzene-Induced Hofmann Rearrangement
作者:Peng Liu、Zhiming Wang、Xianming Hu
DOI:10.1002/ejoc.201101784
日期:2012.4
A simple and efficient method for the synthesis of 1,3-disubstituted ureas and carbamates from amides by using iodosylbenzene as the oxidant is described. Symmetric and asymmetric ureas and carbamates can be prepared by this procedure in up to 98 % yield. Ureidopeptides can also be prepared in good yield by this method.
phenethylamine derivatives, underwent a direct aromatic carbonylation to afford five- or six-membered benzolactams. In the carbonylation, the chelation effect or steric repulsion between Pd(II) and the meta-substituent in the ortho-palladation and the ring sizes of cyclopalladation products that were formed prior to carbonylation were found to generate good site selectivity and increase the reaction rate. In
The invention relates to compounds of formula (I)
wherein R
1-9
, Z, n, X, A, and R
b
have the meaning as cited in the description and the claims. Said compounds are useful as DPP-IV inhibitors. The invention also relates to the preparation of such compounds as well as the production and use thereof as medicament for the treatment of type 2 diabetes mellitus, obesity and lipid disorders.
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