title: Effective enantiodifferentiation of spirochalcogenuranes by the dirhodium method: towards the determination of absolute configurations?
abstract: The properties of chiral spirochalcogenuranes acting as ligands in adducts with a chiral dirhodium tetracarboxylate complex is explored, and the individual adduct species are characterized by low-temperature NMR spectroscopy. Chiral recognition and the determination of enantiomeric composition of the chiral spirochalcogenuranes is easy by evaluating NMR signal dispersions both at low and at room- or slightly elevated temperatures. The uniformity in the signs of 1H dispersion effects and taking reference to the spiroselenurane with known absolute configuration [(S)-(-)-2] indicates that a convenient rule for the determination of absolute configuration in the spirochalcogenurane system can be established on the basis of 1H chemical shift dispersions.
authors.affiliation: Institute for General and Analytical Chemistry of the Budapest University of Technology and Economics, Budapest, Hungary.
authors.forename: Tamás
authors.initials: T
authors.lastname: Gáti
authors.forename: Gábor
authors.initials: G
authors.lastname: Tóth
authors.forename: Józef
authors.initials: J
authors.lastname: Drabowicz
authors.forename: Stefan
authors.initials: S
authors.lastname: Moeller
authors.forename: Edgar
authors.initials: E
authors.lastname: Hofer
authors.forename: Prasad
authors.initials: P
authors.lastname: Polavarapu
authors.forename: Helmut
authors.initials: H
authors.lastname: Duddeck