对映体富集的α-羟基酰胺和β-氨基醇的合成已通过用氢硅烷将α-酮酰胺对映选择性还原而完成。通过使用(EtO)3 SiH作为还原剂,在手性Cu II /(S)-DTBM-SEGPHOS催化剂存在下还原了一系列α-酮酰胺,得到了具有出色对映选择性的相应光学活性α-羟基酰胺。此外,使用相同的手性铜催化剂,然后在(EtO)3 SiH存在下,用四正丁基氟化铵(TBAF)催化剂,一锅完全还原了α-酮酰胺的酮基和酰胺基。相应的手性β-氨基醇衍生物。
Metal free chemoselective reduction of α-keto amides using TBAF as catalyst
作者:N. Chary Mamillapalli、Govindasamy Sekar
DOI:10.1039/c4ra13090a
日期:——
metal and ligand free chemoselective reduction of the keto group and complete reduction of the both keto and amide groups of α-keto amide with hydrosilanes using tetrabutylammoniumflouride (TBAF) as catalyst have been accomplished. This methodology affords an efficient and economic route for the synthesis of biologically important α-hydroxyamides and β-amino alcohols. The other important advantage of
Synthesis of α-Hydroxycarboxylic Acid Anilides via Copper-Catalyzed C–N Coupling of α-Hydroxyamides with Aryl Halides
作者:Qingle Zeng、Zhijie Li、Quan Wen、Lihong Zhou、Xingmei Deng
DOI:10.1055/s-0035-1560473
日期:——
α-hydroxycarboxylic acid anilides via copper-catalyzed chemoselective C–N coupling reactions of α-hydroxyamides and arylhalides is described. This highly selective N-arylation process demonstrates wide substrate scope, cost savings and easy operation. In addition, the chirality of l-3-phenyllactamide is preserved during the reaction. The synthesis of highly important α-hydroxycarboxylic acid anilides via copper-catalyzed
Synthesis of oxazolidine-2,4-diones by a tandem phosphorus-mediated carboxylative condensation–cyclization reaction using atmospheric carbon dioxide
作者:Wen-Zhen Zhang、Tian Xia、Xu-Tong Yang、Xiao-Bing Lu
DOI:10.1039/c5cc01530h
日期:——
A novel access to oxazolidine-2,4-diones using atmospheric CO2 and readily available substrates under mild and transition-metal-free conditions is developed.
Rongalite-Mediated Transition Metal- and Hydride-Free Chemoselective Reduction of α-Keto Esters and α-Keto Amides
作者:Sivaparwathi Golla、Hari Prasad Kokatla
DOI:10.1021/acs.joc.2c00936
日期:2022.8.5
metal- and hydride-free protocol has been developed for the chemoselective reduction of α-keto esters and α-keto amides using rongalite as a reducing agent. Here, rongalite acts as a hydride-free reducing agent via a radical mechanism. This protocol offers the synthesis of a wide range of α-hydroxy esters and α-hydroxy amides with 85–98% yields. This chemoselective method is compatible with other reducible