通过邻羟基芳族醛亚胺和a内酯的多米诺反应,已经实现了对3,4-二氨基苯并二氢吡喃-2-酮的高度对映选择性的合成。值得注意的是,通过使用胍2a获得了顺式产物作为主要产物,而反式产物是双胍盐3•HBAr F 4的主要产物。在两种情况下,以高收率(高达99%),出色的对映选择性(高达99%ee)和非对映选择性(高达> 99:1顺式:反式和98:2 )获得了各种取代的3,4-二氢香豆素。反式:顺式,分别)在温和的反应条件下。
Regioselective Synthesis of Nitrones by Decarboxylative Oxidation of<i>N</i>-Alkyl-<i>α</i>-amino Acids and Application to the Synthesis of 1-Azabicyclic Alkaloids
were prepared by catalytic oxidation of the corresponding chiral pyrrolidines in a regioselective manner. These chiral cyclic nitrones, 17 and 45 are versatile intermediates for the synthesis of optically active nitrogen heterocycles, since stereoselective additions of carbon nucleophiles to these chiral nitrones can be readily performed. Typically, ZnI2-mediated addition of ketene t-butyldimethylsilyl
The present invention relates to novel compounds of general formula (I) wherein the groups X, and R1 to R4 have the meanings given in the description and claims, process for preparing these compounds and their use as for treating, preventing or ameliorating viral infections and their use for treating, preventing or ameliorating diseases which are associated with PLA2G16.
Resolution of RacemicN-Benzyl α-Amino Acids by Liquid-Liquid Extraction: A Practical Method Using a Lipophilic Chiral Cobalt(III) Salen Complex and Mechanistic Studies
作者:Pawel Dzygiel、Toby B. Reeve、Umberto Piarulli、Martin Krupicka、Igor Tvaroska、Cesare Gennari
DOI:10.1002/ejoc.200701101
日期:2008.3
efficient resolution of racemic N-benzyl α-aminoacids (N-Bn-AA) has been achieved by a liquid-liquidextraction process using the lipophilicchiralsalen–cobalt(III) complex [CoIII(3)(OAc)]. As a result of the resolution by extraction, one enantiomer (S) of the N-benzyl α-aminoacid predominated in the aqueous phase, while the other enantiomer (R) was driven into the organic phase by complexation to cobalt
Synthesis of α-Amino Acids through Samarium(II) Iodide Promoted Reductive Coupling of Nitrones with CO2
作者:Alexander Prikhod'ko、Olaf Walter、Thomas A. Zevaco、Jaime Garcia-Rodriguez、Omar Mouhtady、Sandrine Py
DOI:10.1002/ejoc.201200440
日期:2012.7
Several N-benzylnitrones reacted with carbon dioxide in the presence of samarium(II) iodide leading to α-aminoacids as the products of reductive C–C coupling. The best selectivities were observed at a carbon dioxide pressure of 50 bar at ambient temperature. The influences of different functional
几种 N-苄基硝酮在碘化钐 (II) 存在下与二氧化碳反应,生成 α-氨基酸,作为还原性 C-C 偶联的产物。在环境温度和 50 巴的二氧化碳压力下观察到最佳选择性。不同功能的影响
Copper/DIPEA-Catalyzed, Aldehyde-Induced Tandem Decarboxylation–Coupling of Natural α-Amino Acids and Phosphites or Secondary Phosphine Oxides
作者:Dongxu Yang、Depeng Zhao、Lijuan Mao、Linqing Wang、Rui Wang
DOI:10.1021/jo200981h
日期:2011.8.5
copper/DIPEA-catalyzed, aldehyde-induced intermolecular decarboxylative coupling reaction of natural α-amino acids and phosphites or secondary phosphine oxides was developed. In this process, a series of potentially useful ligands for organic synthesis and biologically important unnatural amino acid derivatives (tertiary amino phosphorus compounds) were obtained.