Chiral stationary phase design: A study in optimization

✍ Scribed by Pirkle, William H. ;Bowen, William E.

• Book ID: 102894224
• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 576 KB
• Volume: 17
• Category: Article
• ISSN: 0935-6304
• DOI: 10.1002/jhrc.1240170902

✦ Synopsis

Abstract

A π‐basic, brush‐type chiral stationary phase (CSP) derived from (S)‐N‐(1‐naphthyl)leucine undecenyl ester has been shown to effectively separate the enantiomers of a broad array of π‐acidic analytes. Armed with a mechanistic hypothesis as to how this CSP differentiates between the enantiomers of π‐acidic derivatives of α‐amino acids, the structure of this CSP was modified in a series of steps, each intended to enhance the enantioselectivity of the CSP. Specifically, brush‐type CSPs were prepared from N‐(5‐naphthyl)leucine di‐n‐propyl amide and from N‐(5‐acenaphthyl)leucine di‐n‐propyl amide. The latter selector was also incorporated into a polysiloxane, then coated and bonded to silica. The rationale for each of the structural changes, and its effect on the enantioselectivity of the resulting CSP is described.