HPLC separation and VCD spectroscopy of chiral pyrazoles derived from (5R)-dihydrocarvone

Tur, Eva; Vives, Guillaume; Rapenne, Gwénaël; Crassous, Jeanne; Vanthuyne, Nicolas; Roussel, Christian; Lombardi, Rosina; Freedman, Teresa B.; Nafie, Laurence A.

doi:10.1016/j.tetasy.2007.07.020

Cited by 11 publications

(8 citation statements)

References 39 publications

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“…Over the past several years there has been a rapid growth in the use of VCD to determine the AC of small chiral organic molecules. A large variety of structural types have been examined, including epoxides and cyclopropanes, [55][56][57][58] bicyclic and tricyclic structures, [59][60][61][62][63][64][65][66][67] chiral structures with no chiral center (atropisomer or molecules with axial or helical chirality), [68][69][70][71][72][73][74][75][76][77][78][79][80][81][82][83] sulfur or phosphorus containing compounds, 77,[84][85][86][87][88] flexible molecules, 56,[89][90][91] and other structures that do not fit into any of the above categories. [92][93][94][95][96][97] The following examples highlight the versatility of VCD as a powerful tool for the AC determinations of different types of chiral organ...…”

Section: Determination Of Absolute Configuration Of Small Organic Molmentioning

confidence: 99%

“…Chiral pyrazoles are interesting precursors for the hydrotris(pyrazolyl)borate ligands, which can be used in asymmetric catalysis. 62 Such ligands also have potential use as building blocks for molecular motors. 62 In this collaboration between the groups of Crassous and Nafie, diastereomeric pyrazoles 2a and 2b (shown in Fig.…”

Section: Determination Of Absolute Configuration Of Small Organic Molmentioning

confidence: 99%

“…62 Such ligands also have potential use as building blocks for molecular motors. 62 In this collaboration between the groups of Crassous and Nafie, diastereomeric pyrazoles 2a and 2b (shown in Fig. 7) were synthesized, their ACs were determined, and their tautomeric equilibrium was studied by VCD spectroscopy for the first time.…”

Section: Determination Of Absolute Configuration Of Small Organic Molmentioning

confidence: 99%

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Determination of Absolute Configuration of Chiral Molecules Using Vibrational Optical Activity: A Review

Wang²,

Dukor³

et al. 2011

Appl Spectrosc

291

218

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Determination of the absolute handedness, known as absolute configuration (AC), of chiral molecules is an important step in any field related to chirality, especially in the pharmaceutical industry. Vibrational optical activity (VOA) has become a powerful tool for the determination of the AC of chiral molecules in the solution state after nearly forty years of evolution. VOA offers a novel alternative, or supplement, to X-ray crystallography, permitting AC determinations on neat liquid, oil, and solution samples without the need to grow single crystals of the pure chiral sample molecules as required for X-ray analysis. By comparing the sign and intensity of the measured VOA spectrum with the corresponding ab initio density functional theory (DFT) calculated VOA spectrum of a chosen configuration, one can unambiguously assign the AC of a chiral molecule. Comparing measured VOA spectra with calculated VOA spectra of all the conformers can also provide solution-state conformational populations. VOA consists of infrared vibrational circular dichroism (VCD) and vibrational Raman optical activity (ROA). Currently, VCD is used routinely by researchers in a variety of backgrounds, including molecular chirality, asymmetric synthesis, chiral catalysis, drug screening, pharmacology, and natural products. Although the application of ROA in AC determination lags behind that of VCD, with the recent implementation of ROA subroutines in commercial quantum chemistry software, ROA will in the future complement VCD for AC determination. In this review, the basic principles of the application of VCD to the determination of absolute configuration in chiral molecules are described. The steps required for VCD spectral measurement and calculation are outlined, followed by brief descriptions of recently published papers reporting the determination of AC in small organic, pharmaceutical, and natural product molecules.

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Section: Determination Of Absolute Configuration Of Small Organic Molmentioning

confidence: 99%

Section: Determination Of Absolute Configuration Of Small Organic Molmentioning

confidence: 99%

Section: Determination Of Absolute Configuration Of Small Organic Molmentioning

confidence: 99%

See 1 more Smart Citation

Determination of Absolute Configuration of Chiral Molecules Using Vibrational Optical Activity: A Review

Wang²,

Dukor³

et al. 2011

Appl Spectrosc

291

218

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“…Chiral HPLC has been used for the separation of molecules to assign their absolute configuration using the VCD …”

Section: Resultsmentioning

confidence: 99%

“…Chiral HPLC has been used for the separation of molecules to assign their absolute configuration using the VCD. 23,24 The HPLC chromatogram on a CSP with a polarimetric detection provided for the first time a chiral signature for the flower and leave EOs. The absolute configuration of (−)-cis-chrysanthenyl acetate 1 [(1S,5R,6S)-(−)-2,7,7-trimethylbicyclo[3.1.1]hept-2-en-6-yl acetate] was established in the 1970s by a chemical correlation method on a sample isolated from Centipeda cunninghamii EO.…”

Section: Chiral Signature Of Crude Eos By Chiral Hplc With Online Pmentioning

confidence: 99%

Isolation of the major chiral compounds from Bubonium graveolens essential oil by HPLC and absolute configuration determination by VCD

et al. 2016

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The chirality issues in the essential oils (EOs) of leaves and flowers from Bubonium graveolens were addressed by chiral high-performance liquid chromatography (HPLC) with polarimetric detection and vibrational circular dichroism (VCD). The chemical compositions of the crude oils of three samples were established by gas chromatography / mass spectrometry (GC/MS). The well-known cis-chrysanthenyl acetate (1), oxocyclonerolidol (2), and the recently disclosed cis-acetyloxychrysanthenyl acetate (3), the three major chiral compounds, were isolated by preparative HPLC. The naturally occurring oxocycloneroledol (2), mostly found in the leaf oil (49.4-55.6%), presents a (+) sign in the mobile phase during HPLC on a chiral stationary phase (CSP) with a Jasco polarimetric detection. The naturally occurring cis-chrysanthenyl acetate (1) and cis-acetyloxychrysanthenyl acetate (3), mostly found in the flower EO (35.9-74.9% and 10.0-34.3%, respectively), both present a (-) sign. HPLC on a CSP with polarimetric detection is an unprecedented approach to readily differentiate the flower and leaf EOs according to their chiral signature. The comparison of the experimental and calculated VCD spectra of pure isolated 1, 2, and 3 provided their absolute configuration as being (1S,5R,6S)-(-)-2,7,7-trimethylbicyclo[3.1.1]hept-2-en-6-yl acetate 1, (2R,6R)-(+)-6-ethenyl-2,6-dimethyl-2-(4-methylpent-3-en-1-yl)dihydro-2H-pyran-3(4H)-one) 2 and (1S,5R,6R,7S)-(-)-7-(acetyloxy)-2,6-dimethylbicyclo[3.1.1]hept-2-en-6-yl]methyl acetate 3. Compounds 1, 2, and 3 were already known in B. graveolens but this is the first report of the absolute configuration of (+)-2 and (-)-3. The VCD chiral signatures of the crude oils were also recorded.

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Tautomerism and Structure of Azoles

Ларина

2018

Advances in Heterocyclic Chemistry

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HPLC separation and VCD spectroscopy of chiral pyrazoles derived from (5R)-dihydrocarvone

Cited by 11 publications

References 39 publications

Determination of Absolute Configuration of Chiral Molecules Using Vibrational Optical Activity: A Review

Determination of Absolute Configuration of Chiral Molecules Using Vibrational Optical Activity: A Review

Isolation of the major chiral compounds from Bubonium graveolens essential oil by HPLC and absolute configuration determination by VCD

Tautomerism and Structure of Azoles

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