title: A cyclochiral conformational motif constructed using a robust hydrogen-bonding network.
abstract: A novel conformational motif constructed with a robust intramolecular hydrogen-bonding (H-bonding) network was discovered. A pyrrolidine derivative possessing four identical amide substituents at C(2) and C(5) formed a strong intramolecular H-bonding network consisting of all the amide groups. This conformation yielded a cyclochiral structure with a handedness that depended on the directionality of the H-bonding network. The most stable compound was isolated and applied to the acylative kinetic resolution of secondary alcohol. The handedness of the H-bonding network was biased by the presence of chiral substituents, and the preferred direction could be switched under an external stimulus. A structural analysis using NMR, X-ray crystallography, and theoretical calculation techniques indicated that the conformation of the substituents was highly ordered and depended on the directionality of the H-bonding network.
authors.affiliation: Institute for Chemical Research, Kyoto University , Uji, Kyoto, 611-0011, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Mishiro
authors.forename: Takumi
authors.initials: T
authors.lastname: Furuta
authors.forename: Takahiro
authors.initials: T
authors.lastname: Sasamori
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Hayashi
authors.forename: Norihiro
authors.initials: N
authors.lastname: Tokitoh
authors.forename: Shiroh
authors.initials: S
authors.lastname: Futaki
authors.forename: Takeo
authors.initials: T
authors.lastname: Kawabata
mesh_terms: D018360:Crystallography, X-Ray; D003500:Cyclization; D006860:Hydrogen Bonding; D008314:Malonates / Q000737:chemistry*; D008968:Molecular Conformation; D011725:Pyridines / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D008314:Malonates; D011725:Pyridines; C021249:4-pyrrolidinopyridine; C008314:malonamide