α-Haloalkyl Haloformates and Related Compounds 3.<sup>1</sup>A Facile Synthesis of Symmetrical and Unsymmetrical Ureas<i>via</i>Chloromethyl Carbamates
Abstract Chloromethyl carbamates were prepared by the reaction of chloromethyl chloroformates with amines and found to produce mono-, symmetrically or unsymmetrically di-and trisubstituted ureas including their N-hydroxy and N-alkoxy derivatives in moderate to good yield.
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.
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