Chiral crown ether-anchored polysiloxanes as capillary gas chromatography stationary phases

Abstract

Two chiral stationary phases, named Chirasil-man-18C6-25 and Chirasil-aza-15C5-25, were prepared by hydrosilylating two allyl-crown ethers onto polyhydromethylsiloxane containing 25% Si-H units, respectively. The chiralallyl-crown ethers were synthesized using D-mannitol and (+)-2-amino-1-butanol as chiral sources. Fused-silica capillary gas chromatography showed that the two novel phases had similar characteristics as pieviously reported crown ether bounded polysiloxanes. It was found that the Chirasil-man-18C6-25 phase had enantioselectivity to racemates bearing both an aromatic moiety and a primary amino or hydroxyl group in their structure. This phase also exhibited good thermal stability.