Show simple item record

Files in this item

Thumbnail

Item metadata

dc.contributor.authorHe, Menfang
dc.contributor.authorPiscelli, Bruno
dc.contributor.authorCormanich , Rodrigo
dc.contributor.authorO'Hagan, David
dc.date.accessioned2024-03-06T16:30:08Z
dc.date.available2024-03-06T16:30:08Z
dc.date.issued2024-03-05
dc.identifier299451252
dc.identifierd6d9a3b3-c80e-47af-b6d7-7e87c9bfd7e7
dc.identifier85187010400
dc.identifier.citationHe , M , Piscelli , B , Cormanich , R & O'Hagan , D 2024 , ' Conformational analysis explores the role of electrostatic non-classical CFHC hydrogen bonding interactions in selectively halogenated cyclohexanes ' , The Journal of Organic Chemistry , vol. 89 , no. 6 , pp. 4009–4018 . https://doi.org/10.1021/acs.joc.3c02868en
dc.identifier.issn0022-3263
dc.identifier.otherORCID: /0000-0002-0510-5552/work/155069028
dc.identifier.urihttps://hdl.handle.net/10023/29451
dc.descriptionFunding: Fundação de Amparo à Pesquisa do Estado de São Paulo - 2018/03910-1, 2023/14064-2; China Scholarship Council; Fundo de Apoio ao Ensino, à Pesquisa e Extensão, Universidade Estadual de Campinas - 3472/23en
dc.description.abstractThe conformational equilibria of selectively halogenated cyclohexanes are explored both experimentally (VT-NMR) for 1,1,4,-trifluorocyclohexane 7 and by computational analysis (M06-2X/aug-cc-pVTZ level), with the latter approach extending to a wider range of more highly fluorinated cyclohexanes. Perhaps unexpectedly, 7ax is preferred over the 7eq conformation by ΔG = 1.06 kcal mol–1, contradicting the accepted norm for substituents on cyclohexanes. The axial preference is stronger again in 1,1,3,3,4,5,5,-heptafluorocyclohexane 9 (ΔG = 2.73 kcal mol–1) as the CF2 groups further polarize the isolated CH2 hydrogens. Theoretical decomposition of electrostatic and hyperconjugative effects by natural bond orbital analysis indicated that nonclassical hydrogen bonding (NCHB) between the C-4 fluorine and the diaxial hydrogens at C-2 and C-6 in cyclohexane 7 and 9 largely accounts for the observed bias. The study extended to changing fluorine (F) for chlorine (Cl) and bromine (Br) at the pseudoanomeric position in the cyclohexanes. Although these halogens do not become involved in NCHBs, they polarize the geminal −CHX– hydrogen at the pseudoanomeric position to a greater extent than fluorine, and consequent electrostatic interactions influence conformer stabilities.
dc.format.extent10
dc.format.extent2817847
dc.language.isoeng
dc.relation.ispartofThe Journal of Organic Chemistryen
dc.subjectQD Chemistryen
dc.subjectNDASen
dc.subject.lccQDen
dc.titleConformational analysis explores the role of electrostatic non-classical CFHC hydrogen bonding interactions in selectively halogenated cyclohexanesen
dc.typeJournal articleen
dc.contributor.institutionUniversity of St Andrews. Institute of Behavioural and Neural Sciencesen
dc.contributor.institutionUniversity of St Andrews. EaSTCHEMen
dc.contributor.institutionUniversity of St Andrews. Biomedical Sciences Research Complexen
dc.contributor.institutionUniversity of St Andrews. School of Chemistryen
dc.identifier.doi10.1021/acs.joc.3c02868
dc.description.statusPeer revieweden


This item appears in the following Collection(s)

Show simple item record