38418-19-8Relevant articles and documents
Hydrogen-bond-assisted transition-metal-free catalytic transformation of amides to esters
Huang, Changyu,Li, Jinpeng,Wang, Jiaquan,Zheng, Qingshu,Li, Zhenhua,Tu, Tao
, p. 66 - 71 (2020/11/18)
The amide C-N cleavage has drawn a broad interest in synthetic chemistry, biological process and pharmaceutical industry. Transition-metal, luxury ligand or excess base were always vital to the transformation. Here, we developed a transition-metal-free hydrogen-bond-assisted esterification of amides with only catalytic amount of base. The proposed crucial role of hydrogen bonding for assisting esterification was supported by control experiments, density functional theory (DFT) calculations and kinetic studies. Besides broad substrate scopes and excellent functional groups tolerance, this base-catalyzed protocol complements the conventional transition-metal-catalyzed esterification of amides and provides a new pathway to catalytic cleavage of amide C-N bonds for organic synthesis and pharmaceutical industry. [Figure not available: see fulltext.]
Highly regioselective diels-alder reaction of 9-substituted anthracenes with citraconic anhydride
Khan, Ruhima,Singh, Thokchom Prasanta,Singh, Moirangthem Dhaneshwar
, p. 696 - 700 (2014/04/03)
The regioselectivity in the Diels-Alder reaction of 9-substituted anthracenes having electron-releasing substituents with citraconic anhydride has been investigated. The ortho regioisomer is preferred in all the cases with good yield. The reaction proceed
Diazo preparation via dehydrogenation of hydrazones with "activated" DMSO
Javed, Muhammad I.,Brewer, Matthias
, p. 1789 - 1792 (2008/02/02)
We report that "activated" dimethyl sulfoxide efficiently dehydrogenates hydrazones to the respective diazo species at -78°C. Under optimized conditions, triethylamine hydrochloride is removed quantitatively by vacuum filtration to provide solutions of diazo compounds. Stable diazo species can be isolated in high yield, or alternatively, the direct treatment of these solutions with carboxylic acids provides esters.