title: 3,3'-Diaryl-BINOL phosphoric acids as enantioselective extractants of benzylic primary amines.
abstract: We report that 3,3'-diaryl-BINOL phosphoric acids are effective enantioselective extractants in chiral separation methods based on reactive liquid-liquid extraction. These new extractants are capable of separating racemic benzylic primary amine substrates. The effect of the nature of the substituents at the 3,3'-positions of the host were examined as well as the structure of the substrate, together with important parameters such as the organic solvent, the pH of the aqueous phase, and the host stoichiometry. Titration of the substrate with the host was monitored by FTIR, NMR, UV-Vis, and CD spectroscopy, which provided insight into the structure of the host-guest complex involved in extraction.
authors.affiliation: Stratingh Institute for Chemistry and Center for Systems Chemistry, University of Groningen, Groningen, The Netherlands.
authors.forename: Bastiaan J V
authors.initials: BJ
authors.lastname: Verkuijl
authors.forename: Johannes G
authors.initials: JG
authors.lastname: de Vries
authors.forename: Ben L
authors.initials: BL
authors.lastname: Feringa