Synthesis of 5-(1,2,3-thiadiazol-4-yl)2-methylfuran-3-carboxamides
摘要:
Acetylation of 2-methylfuran-3-carboxamides with acetic anhydride in the presence of magnesium perchlorate yields the corresponding 5-acetyl derivatives; their carboethoxyhydrazones have been synthesized via the reaction with carboethoxyhydrazine. The carboethoxyhydrazones undergo cyclization into the 5-(1,2,3-thiadiazol-4-yl)-2-methylfuran-carboxamides upon treatment with thionyl chloride under conditions of the Hurd-Mori reaction. In the case of (2-methyl-3-furoyl)proline esters, the optical activity is retained after the described transformations.
作者:William I. Nicholson、Fabien Barreteau、Jamie A. Leitch、Riley Payne、Ian Priestley、Edouard Godineau、Claudio Battilocchio、Duncan L. Browne
DOI:10.1002/anie.202106412
日期:2021.9.27
The direct mechanochemical amidation of esters by ball milling is described. The operationally simple procedure requires an ester, an amine, and substoichiometric KOtBu and was used to prepare a large and diverse library of 78 amide structures with modest to excellent efficiency. Heteroaromatic and heterocyclic components are specifically shown to be amenable to this mechanochemical protocol. This
Manganese Catalyzed Direct Amidation of Esters with Amines
作者:Zhengqiang Fu、Xinghua Wang、Sheng Tao、Qingqing Bu、Donghui Wei、Ning Liu
DOI:10.1021/acs.joc.0c02478
日期:2021.2.5
metal catalyzed amidations remains a challenge. Here, a manganese(I)-catalyzed method for the direct synthesis of amides from a various number of esters and amines is reported with unprecedented substrate scope using a low catalyst loading. A wide range of aromatic, aliphatic, and heterocyclic esters, even in fattyacid esters, reacted with a diverse range of primary aryl amines, primary alkyl amines