Forjan Davorka Moslavac, Kontrec Darko, Vinković Vladimir
Laboratory for Stereoselective Catalysis and Biocatalysis, Ruder Bosković Institute, P.O. Box 180, Bijenicka Cesta 54, HR-10002 Zagreb, Croatia.
Chirality. 2006 Nov;18(10):857-69. doi: 10.1002/chir.20329.
The replacement of the N-H hydrogen of the secondary amide-tethered Pirkle-concept N-(3,5-dinitrobenzoyl)-L-leucine derived chiral stationary phase with various pi-basic or aliphatic groups improved the chiral discrimination ability of new chiral stationary phases, based on the leucine- or alanine-derived chiral selector, for the enantiomers of various racemic neutral analytes with amide functional groups. Retention times decreased while separation and resolution factors increased, thus proving the role of pi-donor aromatic unit as an electron-rich shield in the front of a silica surface. In general, chiral stationary phase (CSP) 5 with the 3,5-dimethylphenyl unit showed best performance, while CSP 3, with phenyl unit, and CSP 7, with 1-naphthyl unit in the tertiary amide connecting tether, were less efficient.
用各种π-碱性或脂肪族基团取代基于Pirkle概念的、由二级酰胺连接的N-(3,5-二硝基苯甲酰基)-L-亮氨酸衍生的手性固定相中的N-H氢，提高了基于亮氨酸或丙氨酸衍生的手性选择剂的新型手性固定相对各种具有酰胺官能团的外消旋中性分析物对映体的手性识别能力。保留时间缩短，而分离度和分辨率因子增加，从而证明了π-供体芳香单元在硅胶表面前部作为富电子屏蔽的作用。一般来说，具有3,5-二甲基苯基单元的手性固定相（CSP）5表现出最佳性能，而在叔酰胺连接链中具有苯基单元的CSP 3和具有1-萘基单元的CSP 7效率较低。
