Enantiomeric Analysis of Chiral Isotopomers via Microwave Three-Wave Mixing

Satterthwaite, Lincoln; Pérez, Cristóbal; Steber, Amanda L.; Finestone, Dylan; Broadrup, Robert L.; Patterson, David

doi:10.1021/acs.jpca.9b02115

Cited by 16 publications

(9 citation statements)

References 27 publications

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“…Both the assignment of absolute configuration and the measurement of the enantiomeric excess are accomplished without the need of any reference samples of the analyte. We note that a different approach to using MRR to perform chiral analysis—three‐wave mixing rotational spectroscopy [54–56] —has recently been described for molecules that are chiral by virtue of deuteration. However, in its present state of development this technique cannot assign the AC of a sample because no method has been demonstrated that can determine the absolute phase of the chiral signal.…”

Section: Discussionmentioning

confidence: 99%

Enantioselective Synthesis of Enantioisotopomers with Quantitative Chiral Analysis by Chiral Tag Rotational Spectroscopy

et al. 2022

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Fundamental to the synthesis of enantioenriched chiral molecules is the ability to assign absolute configuration at each stereogenic center, and to determine the enantiomeric excess for each compound. While determination of enantiomeric excess and absolute configuration is often considered routine in many facets of asymmetric synthesis, the same determinations for enantioisotopomers remains a formidable challenge.Here, we report the first highly enantioselective metalcatalyzed synthesis of enantioisotopomers that are chiral by virtue of deuterium substitution along with the first general spectroscopic technique for assignment of the absolute configuration and quantitative determination of the enantiomeric excess of isotopically chiral molecules. Chiral tag rotational spectroscopy uses noncovalent chiral derivatization, which eliminates the possibility of racemization during derivatization, to perform the chiral analysis without the need of reference samples of the enantioisotopomer.

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Section: Discussionmentioning

confidence: 99%

Enantioselective Synthesis of Enantioisotopomers with Quantitative Chiral Analysis by Chiral Tag Rotational Spectroscopy

et al. 2022

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“…Kawasaki et al found that the chirality of the S and R enantiomers was mainly attributable to the very small difference between the C-D and C-H bond-lengths associated with the alpha carbon of glycine [20][21][22]. The development of a highly sensitive method for the detection of isotopic chirality in meteoritic organic compounds such as amino acids [23] with an achiral framework and isotopic enrichment therefore remains a challenging subject [24,25].…”

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confidence: 99%

The chirality of isotopomers of glycine compared using next‐generationQTAIM

Nie

Yang

et al. 2022

Int J of Quantum Chemistry

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The effect of a deuterium (D) or tritium (T) isotope bonded to the alpha carbon of glycine is determined without the need to apply external forces, for example, electric fields or using normal mode analysis. Isotopic effects were accounted for using the mass-dependent diagonal Born-Oppenheimer energy correction (DBOC) at the CCSD level of theory. We calculated the stress tensor trajectories of the dominant C-N bond within next generation quantum theory of atoms in molecules (NG-QTAIM). S-character chirality was discovered using the stress tensor trajectories, instead of the Cahn-Ingold-Prelog (CIP) rules, for ordinary glycine. The S-character chirality was preserved after the substitution of the H on the alpha carbon for a D isotope but transformed to R-character chirality after replacement with the T isotope. This reversal of the chirality depending on the presence of a single D or T isotope bound to the alpha carbon adds to the debate on the nature of the extraterrestrial origins of chirality in simple amino acids. We demonstrate that NG-QTAIM is a promising tool for understanding isotopic induced electronic charge density changes, useful in analysis of infrared (IR) or circular dichroism (CD) spectra explaining changes in mode couplings and bands intensities or sign.

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“…Both the assignment of absolute configuration and the measurement of the enantiomeric excess are accomplished without the need of any reference samples of the analyte. We note that a different approach to using MRR to perform chiral analysis-three-wave mixing rotational spectroscopy [54][55][56] has recently been described for molecules that are chiral by virtue of deuteration. However, in its present state of development this technique cannot assign the AC of a sample because no method has been demonstrated that can determine the absolute phase of the chiral signal.…”

Section: Discussionmentioning

confidence: 99%

Enantioselective Synthesis of Enantioisotopomers with Quantitative Chiral Analysis by Chiral Tag Rotational Spectroscopy

et al. 2022

View full text Add to dashboard Cite

Fundamental to the synthesis of enantioenriched chiral molecules is the ability to assign absolute configuration at each stereogenic center, and to determine the enantiomeric excess for each compound. While determination of enantiomeric excess and absolute configuration is often considered routine in many facets of asymmetric synthesis, the same determinations for enantioisotopomers remains a formidable challenge. Here, we report the first highly enantioselective metal‐catalyzed synthesis of enantioisotopomers that are chiral by virtue of deuterium substitution along with the first general spectroscopic technique for assignment of the absolute configuration and quantitative determination of the enantiomeric excess of isotopically chiral molecules. Chiral tag rotational spectroscopy uses noncovalent chiral derivatization, which eliminates the possibility of racemization during derivatization, to perform the chiral analysis without the need of reference samples of the enantioisotopomer.

show abstract

Enantiomeric Analysis of Chiral Isotopomers via Microwave Three-Wave Mixing

Cited by 16 publications

References 27 publications

Enantioselective Synthesis of Enantioisotopomers with Quantitative Chiral Analysis by Chiral Tag Rotational Spectroscopy

Enantioselective Synthesis of Enantioisotopomers with Quantitative Chiral Analysis by Chiral Tag Rotational Spectroscopy

The chirality of isotopomers of glycine compared using next‐generationQTAIM

Enantioselective Synthesis of Enantioisotopomers with Quantitative Chiral Analysis by Chiral Tag Rotational Spectroscopy

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