Some Inherently Chiral Chromophores—Empirical Rules and Quantum Chemical Calculations

Kwit, Marcin; Skowronek, Paweł; Gawroński, Jacek; Frelek, Jadwiga; Woźnica, Magdalena; Butkiewicz, Aleksandra

doi:10.1002/9781118120392.ch2

Cited by 11 publications

(23 citation statements)

References 108 publications

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“…39,40 This also holds true in the case of the studied molecule. Comparison of the ECD spectra of individual conformers shows that there is no characteristic band (with the unchanged position and sign), which could be used for the C17 center configuration assignment (Figs.…”

Section: Resultssupporting

confidence: 69%

Reassignment of the absolute configuration of plakinidone from the sponge consortium Plakortis halichondrioides–Xestospongia deweerdtae using a combination of synthesis and a chiroptical approach

Jiménez-Romero

Rode

Rodrı́guez

2016

Tetrahedron: Asymmetry

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Recent work by Wu et al. in connection with the first synthesis of the marine natural product plakinidone revealed that the most salient feature of its purported structure, a six-membered perlactone moiety, was in fact a five-membered lactone, i.e. a 3-methyl-4-hydroxy-2(5H)-furanone or tetronic acid ring. With the planar structure of plakinidone confidently revised, we undertook a new investigation to unambiguously establish its absolute configuration. Upon preparing two stable derivatives 1 and 5 from a sample of naturally occurring plakinidone extracted from the sponge association Plakortis halichondriodes–Xetospongia deweerdtae, the absolute configuration was assigned by synthesis and vibrational and electronic circular dichroism (VCD and ECD) measurements in combination with density functional theory calculations at the B3LYP/aug-cc-pVDZ/PCM(CH3CN) level of theory. Our combined efforts and the agreement between the experimental and calculated VCD/ECD spectra of 1 revealed that the absolute configuration of plakinidone was in fact (11S,17R) and not the formerly reported (11S,17S) diastereomer assigned by Wu et al.. Therefore, we propose that natural plakinidone is accurately represented by structure 12.

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Section: Resultssupporting

confidence: 69%

Reassignment of the absolute configuration of plakinidone from the sponge consortium Plakortis halichondrioides–Xestospongia deweerdtae using a combination of synthesis and a chiroptical approach

Jiménez-Romero

Rode

Rodrı́guez

2016

Tetrahedron: Asymmetry

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“…To illustrate how the static mechanism operates on the present compounds, we will make use of sector rules. Semi-empirical sector rules have been very popular in the past as tools to predict ECD spectra of various molecules [ 61 , 62 ]. Their use is discouraged today in favor of non-empirical methods of analysis, however, the basic theory behind sector rules remains valid and offers a simple and effective way for understanding the relation between molecular structure and ECD signals.…”

Section: Discussionmentioning

confidence: 99%

How and How Much Molecular Conformation Affects Electronic Circular Dichroism: The Case of 1,1-Diarylcarbinols

Padula

2018

Molecules

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Chiroptical spectra such as electronic circular dichroism (ECD) are said to be much more sensitive to conformation than their non-chiroptical counterparts, however, it is difficult to demonstrate such a common notion in a clear-cut way. We run DFT and TDDFT calculations on two closely related 1,1-diarylmethanols which show mirror-image ECD spectra for the same absolute configuration. We demonstrate that the main reason for the different chiroptical response of the two compounds lies in different conformational ensembles, caused by a single hydrogen-to-methyl substitution. We conclude that two compounds, having the same configuration but different conformation, may exhibit mirror-image ECD signals, stressing the importance and impact of conformational factors on ECD spectra.

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“…Electronic circular dichroism (ECD) of molecules having homo‐ or heteroannular diene moiety are well investigated by both experimental and theoretical studies . As one of the interesting things, Burgstahler et al found that the positive sign of the CD spectrum of 1,3‐diene steroid is inverted to the negative in its methyl substituted derivative, and rationalized it qualitatively as P‐ or M‐chirality, indicated in Scheme .…”

Section: Methodsmentioning

confidence: 99%

“…Electronic circular dichroism (ECD) of molecules having homo-or heteroannular diene moiety are well investigated by both experimental and theoretical studies. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] As one of the interesting things, Burgstahler et al 4 found that the positive sign of the CD spectrum of 1,3-diene steroid is inverted to the negative in its methyl substituted derivative, and rationalized it qualitatively as P-or M-chirality, indicated in Scheme 1. Moriarty et al 7 proposed "diene quadrant rule" that the cubic space is divided into quadrants in order to assign relative signs of the rotatory contribution of the diene and axial substituents.…”

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confidence: 99%

Theoretical Electronic Circular Dichroism Study of 1,3‐Diene Derivatives for the Elucidation of ECD Spectra of 1,3‐Cyclohexadiene and Its Derivatives

Nakayama¹,

Gotō

2015

Chirality

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The origin of P- or M-chirality of methyl substituted 1,3-cyclohexadienes are elucidated by time-dependent density functional theory (TD-DFT) calculation of 1,3-cyclohexadiene derivatives and acyclic 1,3-dienes. The sign-inversion of the rotatory strength of the lowest excited state between 1,3-cyclohexadiene and (5R)-axial-methyl-1,3-cyclohexadiene is caused by the conformation around the (C=)C-C(-Me) dihedral angle. The correlation between the sign of the rotatory strength and conformation has been found not only in methyl substituted derivatives but also fluoro substituted compounds.

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Some Inherently Chiral Chromophores—Empirical Rules and Quantum Chemical Calculations

Cited by 11 publications

References 108 publications

Reassignment of the absolute configuration of plakinidone from the sponge consortium Plakortis halichondrioides–Xestospongia deweerdtae using a combination of synthesis and a chiroptical approach

Reassignment of the absolute configuration of plakinidone from the sponge consortium Plakortis halichondrioides–Xestospongia deweerdtae using a combination of synthesis and a chiroptical approach

How and How Much Molecular Conformation Affects Electronic Circular Dichroism: The Case of 1,1-Diarylcarbinols

Theoretical Electronic Circular Dichroism Study of 1,3‐Diene Derivatives for the Elucidation of ECD Spectra of 1,3‐Cyclohexadiene and Its Derivatives

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