title: Chiral recognition in cucurbituril cavities.
abstract: For the first time, achiral cucurbiturils (CBs) were endowed with significant enantiomeric and distereomeric discrimination by incorporating a strong chiral binder. Calorimetric, nuclear magnetic, light-scattering, and mass spectral studies revealed that (S)-2-methylbutylamine (as a strong binder) can be discriminated by two enantiomeric supramolecular hosts, composed of CB[6] and (R)- or (S)-2-methylpiperazine, with an unprecedented 95% enantioselectivity in aqueous NaCl solution. This is the highest enantioselectivity ever reported for a supramolecular system derived from an achiral host. Similarly, CB[7], with a larger cavity, exhibited diastereoselectivities up to 8 times higher for diastereomeric dipeptides, as demonstrated for L-Phe-L-Leu-NH3+ versus L-Phe-D-Leu-NH3+.
authors.affiliation: Entropy Control Project, ICORP, JST, 4-6-3 Kamishinden, Toyonaka 560-0085, Japan.
authors.forename: Mikhail V
authors.initials: MV
authors.lastname: Rekharsky
authors.forename: Hatsuo
authors.initials: H
authors.lastname: Yamamura
authors.forename: Chika
authors.initials: C
authors.lastname: Inoue
authors.forename: Masao
authors.initials: M
authors.lastname: Kawai
authors.forename: Issey
authors.initials: I
authors.lastname: Osaka
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Arakawa
authors.forename: Kouhei
authors.initials: K
authors.lastname: Shiba
authors.forename: Akihiro
authors.initials: A
authors.lastname: Sato
authors.forename: Young Ho
authors.initials: YH
authors.lastname: Ko
authors.forename: Narayanan
authors.initials: N
authors.lastname: Selvapalam
authors.forename: Kimoon
authors.initials: K
authors.lastname: Kim
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Inoue