title: Nitrogen Stereodynamics and Complexation Phenomena as Key Factors in the Deprotonative Dynamic Resolution of Alkylideneaziridines: A Spectroscopic and Computational Study.
abstract: The present work is aimed at shedding light on the origin of the stereoselectivity observed in the reactions of chiral heterosubstituted organolithiums, generated by lithiation of alkylideneaziridines. Factors such as the nitrogen inversion barrier, the stereochemistry at the nitrogen atom, the substitution pattern of the alkylideneaziridines, and the reaction conditions are taken into consideration. The interplay between nitrogen stereodynamics and complexation phenomena seems to be crucial in determining the stereochemical outcome of the lithiation/trapping sequence. The findings were rationalized by a synergistic use of NMR experiments, run on the lithiated intermediates, alongside computational data. It has been demonstrated that, in such systems, the stereochemistry-determining step is the deprotonation reaction, and a model based on a deprotonative dynamic resolution has been proposed. Such findings could find application in dynamic systems other than aziridines.
authors.affiliation: †Department of Pharmacy-Drug Sciences, University of Bari "A. Moro", Via E. Orabona 4, Bari 70125, Italy.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Degennaro
authors.affiliation: ‡Department of Chemistry and Pharmacy, University of Sassari, Via Vienna 2, Sassari 07100, Italy.
authors.forename: Luisa
authors.initials: L
authors.lastname: Pisano
authors.affiliation: †Department of Pharmacy-Drug Sciences, University of Bari "A. Moro", Via E. Orabona 4, Bari 70125, Italy.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Parisi
authors.affiliation: †Department of Pharmacy-Drug Sciences, University of Bari "A. Moro", Via E. Orabona 4, Bari 70125, Italy.|§Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, United Kingdom.
authors.forename: Rosmara
authors.initials: R
authors.lastname: Mansueto
authors.affiliation: §Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, United Kingdom.
authors.forename: Guy J
authors.initials: GJ
authors.lastname: Clarkson
authors.affiliation: §Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, United Kingdom.
authors.forename: Michael
authors.initials: M
authors.lastname: Shipman
authors.affiliation: †Department of Pharmacy-Drug Sciences, University of Bari "A. Moro", Via E. Orabona 4, Bari 70125, Italy.
authors.forename: Renzo
authors.initials: R
authors.lastname: Luisi
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D001388:Aziridines / Q000737:chemistry*; D003198:Computer Simulation; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009584:Nitrogen / Q000737:chemistry*; D011789:Quantum Theory; D013237:Stereoisomerism
chemical_list: D000475:Alkenes; D001388:Aziridines; D009584:Nitrogen