Chirality without stereoisomers : insight from the helical response of bond electrons
Abstract
Theassociation between molecular chirality and helical characteristics known asthe chirality-helicity equivalence is determined, for the first time, byquantifying a chirality-helicity measure consistent with photoexcitationcircular dichroism experiments. This is demonstrated using a formally achiral SN2reaction and a chiral SN2 reaction. Both the achiral and chiral SN2reactions possess significant values of the chirality-helicity measure anddisplay a Walden inversion, i.e. an inversion of the chirality between thereactant and product. We also track the chirality-helicity measure along thereaction path and discover the presence of chirality at the transition stateand two intermediate structures for both reactions. We demonstrate the need forthe chirality-helicity measure to differentiate between steric effects due toeclipsed conformations and chiral behaviors in formally achiral species. Weexplain the significance of this work for asymmetricsynthetic reactions including the intermediate structures where the Cahn–Ingold–Prelog (CIP) rulescannot be used.
Citation
Xu , T , Nie , X , Li , S , Yang , Y , Früchtl , H , van Mourik , T , Kirk , S R , Paterson , M J , Shigeta , Y & Jenkins , S 2021 , ' Chirality without stereoisomers : insight from the helical response of bond electrons ' , ChemPhysChem , vol. Early View . https://doi.org/10.1002/cphc.202100397
Publication
ChemPhysChem
Status
Peer reviewed
ISSN
1439-4235Type
Journal article
Rights
Copyright © 2021 Wiley-VCH GmbH. This work has been made available online in accordance with publisher policies or with permission. Permission for further reuse of this content should be sought from the publisher or the rights holder. This is the author created accepted manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at https://doi.org/10.1002/cphc.202100397
Description
The National Natural Science Foundation of China is gratefully acknowledged, project approval number: 21673071. The One Hundred Talents Foundation of Hunan Province is also gratefully acknowledged for the support of S.J. and S.R.K.Collections
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