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
Catalytic, Enantioselective N-Acylation of Lactams and Thiolactams Using Amidine-Based Catalysts
作者:Xing Yang、Valentina D. Bumbu、Peng Liu、Ximin Li、Hui Jiang、Eric W. Uffman、Lei Guo、Wei Zhang、Xuntian Jiang、K. N. Houk、Vladimir B. Birman
DOI:10.1021/ja306766n
日期:2012.10.24
contrast to alcohols and amines, racemic lactams and thiolactams cannot be resolved directly via enzymatic acylation or classical resolution. Asymmetric N-acylation promoted by amidine-based catalysts, particularly Cl-PIQ 2 and BTM 3, provides a convenient method for the kinetic resolution of these valuable compounds and often achieves excellent levels of enantioselectivity in this process. Density
Synthesis and determination of the absolute stereochemistry of the enantiomers of adrafinil and modafinil
作者:Antonio Osorio-Lozada、Thomas Prisinzano、Horacio F. Olivo
DOI:10.1016/j.tetasy.2004.10.019
日期:2004.11
Both enantiomers of modafinil, adrafinil, modafinic acid and ethyl modafinate were prepared from the diastereomers formed by reacting racemic β-sulfinyl carboxylic acid with (4R)-phenyl-thiazolidinethione. The absolutestereochemistry of the sulfoxide group was confirmed via X-ray analysis of one of the thiazolidinethione diastereomers.
Synthesis of the Anti-HIV Agent (−)-Hyperolactone C by Using Oxonium Ylide Formation-Rearrangement
作者:David M. Hodgson、Stanislav Man
DOI:10.1002/chem.201101082
日期:2011.8.22
Starting from readily available (S)‐styrene oxide an asymmetric synthesis is described of the naturally occurring anti‐HIV spirolactone (−)‐hyperolactoneC, which possesses adjacent fully substituted stereocenters. The key step involves a stereocontrolled RhII‐catalysed oxonium ylide formation–[2,3] sigmatropic rearrangement of an α‐diazo‐β‐ketoester bearing allylic ether functionality. From the resulting