title: Enantioselective Preparation, Conformational Analysis and Absolute Configuration of Highly Substituted Aziridines.
abstract: The first example of organocatalytic aziridination reaction of α-substituted-α,β-unsaturated ketones is presented. The reaction was found to be highly enantio- and diastereoselective, yielding N-tosylated aziridines. Low-temperature nuclear magnetic resonance (NMR) spectra allowed for the determination of the N-inversion barrier, that was found to be quite lower with respect to unsubstituted aziridines. A thorough conformational analysis supported by low-temperature NMR data allowed for the determination of the absolute configuration of the main stereoisomer by means of time-dependent Density Functional Theory simulation of the electronic circular dichroism spectra.
authors.affiliation: Department of Industrial Chemistry "Toso Montanari", University of Bologna, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Bencivenni
authors.affiliation: Department of Industrial Chemistry "Toso Montanari", University of Bologna, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Righi
authors.affiliation: Department of Industrial Chemistry "Toso Montanari", University of Bologna, Italy.
authors.forename: Lodovico
authors.initials: L
authors.lastname: Lunazzi
authors.affiliation: Department of Industrial Chemistry "Toso Montanari", University of Bologna, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Ranieri
authors.affiliation: Department of Industrial Chemistry "Toso Montanari", University of Bologna, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Mancinelli
authors.affiliation: Department of Industrial Chemistry "Toso Montanari", University of Bologna, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Mazzanti
keywords: DFT calculations; absolute configuration; aziridines; dynamic-NMR; organocatalysis