获得(R)-(-)(1),(S)-(+)-3-(1-吡咯基)丙基-N-(3,5-二硝基苯甲酰基)-α-苯基甘氨酸盐的合成路线(2)和描述了派生词。第一步,使用Clauson-Kaas方法制备吡咯衍生物。由于吡咯基团对酸性条件的敏感性,使用碱性条件进行第二步的酯化反应。涉及立体发生中心的互变异构平衡诱导产物差向异构。用高度受阻的碱质子海绵®替代DMAP和Et 3 N ,可提供最终产品,且不消旋。的EE 1,2在存在光学活性Eu(tfc)3的情况下,通过1 H NMR分析确定相应的甲酯(3和4)。差向异构化没有在羧酸盐(制备观察到5 - 8)。
Synthesis of new C3 symmetric amino acid- and aminoalcohol-containing chiral stationary phases and application to HPLC enantioseparations
作者:Jeongjae Yu、Daniel W. Armstrong、Jae Jeong Ryoo
DOI:10.1002/chir.22766
日期:2018.1
We recently reported a new C3‐symmetric (R)‐phenylglycinol N‐1,3,5‐benzenetricarboxylic acid‐derived chiral high‐performance liquid chromatography (HPLC) stationaryphase (CSP 1) that demonstrated better results as compared to a previously described N‐3,5‐dintrobenzoyl (DNB) (R)‐phenylglycinol‐derived CSP. Over a decade ago, (S)‐leucinol, (R)‐phenylglycine, and (S)‐leucine derivatives were used as
Synthesis and application of
<i>N</i>
‐3,5‐dinitrobenzoyl and C
<sub>3</sub>
symmetric diastereomeric chiral stationary phases
作者:Jeong Jae Yu、Jae Jeong Ryoo
DOI:10.1002/chir.23415
日期:2022.4
Three diastereomeric chiral compounds, namely, (R,R)-(+)-2-amino-1,2-diphenylethanol, (1S,2R)-(+)-2-amino-1,2-diphenylethanol, and (1R,2R)-(+)-1,2-diphenylethylenediamine were used as starting materials for preparing three N-3,5-dinitrobenzoyl derivative chiral stationary phases (CSPs) (CSP 1, 2, and 3) and three C3 symmetric CSPs (CSP 4, 5, and 6). The six newly prepared CSPs were applied to the chiral
Preparation of Two New Diasteromeric Chiral Stationary Phases Based on (+)-(18-Crown-6)-2,3,11,12-tetracarboxylic Acid and (R)- or (S)-1-(1-Naphthyl)ethylamine and Chiral Tethering Group Effect on the Chiral Recognition
effect on the chiral recognition while (S)-1-(1-naphthyl)ethylamine and (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid constituting CSP 2 were concluded to show an uncooperative (“mismatched”) effect on the chiral recognition. From these results, it was concluded that (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid can be successfully used as a chiral tethering group for the preparation of new CSPs
tested as chiral solvating agents (CSAs) in 1H NMR experiments with rac-N-3,5-dinitrobenzoylphenylglycine methyl ester in order to determine the influence of different structural features on the enantiodiscrimination capabilities. Some selected compounds were tested with other racemic analytes, still leading to enantiodiscrimination. The enantiodiscrimination conditions were then optimized for the best
Enantioselective Hydrolysis of N-Acylated α-Amino Esters at a Biphasic Interface: Tandem Reaction Kinetic Resolution Using a Chiral Complexing Agent
作者:Seth E. Snyder、William H. Pirkle
DOI:10.1021/ol026517s
日期:2002.9.1
Highly enantioselective hydrolytic kinetic resolutions of esters derived from N-acylated alpha-amino acids proceed rapidly at hydorcarbon/water interfaces in the presence of a proline-derived chiral selector. When performed in tandem with an enantioselective biphasic esterification reaction, esters of 100% enantiomeric excess are obtained.