Preparation and use of hydantion-based chiral stationary phases

Abstract

Starting from α-naphthyl 4-pentenyl ketone, hydantoin-based chiral stationary phase 6a has been prepared. Chiral stationary phase 6a has proven to be quite effective for the separation of the enantiomers of hundreds of 3,5-dinitrobenzamides derived from amino acids, amino esters, amino amides, amino phosphates, amino alcohols and amines. A chiral recognition model involving three simultaneous stereochemically-dependent interactions is advanced to account for the observed elution orders of the enantiomers. On the basis of the chiral recognition model, a rational improvement was made in the design of the hydantoin chiral stationary phase. For example, enahancing the π-basicity of the naphthyl system [chiral stationary phase 6b, derived from ( R)-5(6,7-dimethyl-1-naphthyl)-5-(5-triethoxysilyl)hydantoin] has led to significantly imprved performance relative to phase 6a, which lacks the 6,7-dimethyl groups. Ring-alkylated chiral stationary phase 6c has also been prepared and evaluated relative to phase 6a.