Highly selective generation of urethanes from amines, carbon dioxide and alkyl chlorides
作者:William D. McGhee、Yi Pan、Dennis P. Riley
DOI:10.1039/c39940000699
日期:——
Generation of carbamate anions from either a primary or secondary amine, carbon dioxide and a stoichiometric amount of a pentaalkylguanidine followed by the addition of alkyl chlorides gives high yields of urethanes.
A novel synthesis of carbamate ester using carbondioxide as a direct material is reported in this article. The direct reaction of carbondioxide, aliphatic amines, and alkyl halides was found to give the corresponding alkyl carbamate esters in good yields. Reactions using secondary alkyl bromides gave carbamate esters in higher yields than those using primary or tertiary alkyl bromides. The carbamate
Carbamate Synthesis Using a Shelf‐Stable and Renewable C
<sub>1</sub>
Reactant
作者:Zoltán Dobi、B. Narendraprasad Reddy、Evelien Renders、Laurent Van Raemdonck、Carl Mensch、Gilles De Smet、Chen Chen、Charles Bheeter、Sergey Sergeyev、Wouter A. Herrebout、Bert U. W. Maes
DOI:10.1002/cssc.201900406
日期:2019.7.5
4‐Propylcatechol carbonate is a shelf‐stable, renewable C1 reactant. It is easily prepared from renewable 4‐propylcatechol (derived from wood) and dimethyl carbonate (derived from CO2) using a reactive distillation system. In this work, the 4‐propylcatechol carbonate is used for the two‐step synthesis of carbamates under mild reaction conditions. In the first step, 4‐propylcatechol carbonate is treated
ecologically safer way to synthesize protected amines, the reactions of amines with benzyl halides under CO2 atmosphere were systematically examined. For primary amines, the CO2-inserted products were obtained in higher yields in the presence of DBU as a base, under a high pressure of CO2, and in a low-polarity solvent (toluene/hexane 1 : 1). Secondary amines gave only low yields of CO2-inserted products
为了找到一种有用、实用且生态更安全的合成受保护胺的方法,系统地研究了胺与卤代苄在 CO2 气氛下的反应。对于伯胺,在 DBU 作为碱的存在下,在 的高压下,在低极性溶剂(甲苯/己烷 1:1)中,以更高的产率获得了插入 的产物。仲胺仅产生低产率的 插入产物。