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
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
Resolution of Pentafluorophenyl Active Esters Using (S)-4-Phenyloxazolidin-2-thione
作者:Jason Eames、Najla Al Shaye、Tom Broughton、Elliot Coulbeck
DOI:10.1055/s-0028-1088218
日期:2009.4
A series of structurally related racemic pentafluorophenyl active esters were resolved using an equimolar amount of (S)-4-phenyloxazolidin-2-thione. The levels of diastereocontrol were found to be excellent (>86% de at Ë30% conversion).
The parallelkineticresolution of racemic pentafluorophenyl 2-phenylpropionate using an equimolar combination of quasi-enantiomeric oxazolidin-2-ones is discussed. The levels of diastereoselectivity were excellent (>90% de) leading to separable quasi-enantiomeric oxazolidin-2-one adducts in good yield. This methodology was subsequently used to resolve a series of 2-aryl propionic and butanoic acids