Enantioselective synthesis of ammonium cations

Walsh, Mark P.; Phelps, Joseph M.; Lennon, Marc E.; Yufit, Dmitry S.; Kitching, Matthew O.

doi:10.1038/s41586-021-03735-5

Cited by 44 publications

(35 citation statements)

References 53 publications

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“…There is also similar research being conducted on P chiral centers e.g., Ref. [68], as well as N [69,70]; however, the stereochemistry of the N atom makes it the most difficult heteroatom to control [70].…”

Section: Heteroatom Chiralitymentioning

confidence: 99%

Chirality in Organic and Mineral Systems: A Review of Reactivity and Alteration Processes Relevant to Prebiotic Chemistry and Life Detection Missions

et al. 2022

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Chirality is a central feature in the evolution of biological systems, but the reason for biology’s strong preference for specific chiralities of amino acids, sugars, and other molecules remains a controversial and unanswered question in origins of life research. Biological polymers tend toward homochiral systems, which favor the incorporation of a single enantiomer (molecules with a specific chiral configuration) over the other. There have been numerous investigations into the processes that preferentially enrich one enantiomer to understand the evolution of an early, racemic, prebiotic organic world. Chirality can also be a property of minerals; their interaction with chiral organics is important for assessing how post-depositional alteration processes could affect the stereochemical configuration of simple and complex organic molecules. In this paper, we review the properties of organic compounds and minerals as well as the physical, chemical, and geological processes that affect organic and mineral chirality during the preservation and detection of organic compounds. We provide perspectives and discussions on the reactions and analytical techniques that can be performed in the laboratory, and comment on the state of knowledge of flight-capable technologies in current and future planetary missions, with a focus on organics analysis and life detection.

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Section: Heteroatom Chiralitymentioning

confidence: 99%

Chirality in Organic and Mineral Systems: A Review of Reactivity and Alteration Processes Relevant to Prebiotic Chemistry and Life Detection Missions

et al. 2022

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“…In UHINUV, quinoline, benzyl, and phenyl C-HÁ Á ÁBr contacts with the same cation are found. The N-benzylcinchoninium chloride salt has also been employed in a cocrystal resolution of BINOL (WOMQUK01; Walsh et al, 2021).…”

Section: Figurementioning

confidence: 99%

Crystal structures of anhydrous and hydrated N-benzylcinchonidinium bromide

Janzen¹,

Butler²,

Reinheimer³

2022

Acta Cryst E

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N-benzylcinchonidinium bromide, C26H29N2O+·Br−, with the systematic name (R)-[(2S,4S,5R)-1-benzyl-5-ethenyl-1-azoniabicyclo[2.2.2]octan-2-yl](quinolin-4-yl)methanol bromide, is a quaternary ammonium salt of the cinchona alkaloid cinchonidine. This salt is widely used as a chiral phase-transfer catalyst and chiral resolution agent. Both classical and non-classical hydrogen-bonding interactions, as well as anion effects have been shown to play key mechanistic roles in the catalysis of cinchona alkaloids. In an effort to understand the effects of water on these intermolecular interactions, the structures of anhydrous N-benzylcinchonidinium bromide, (I), and the sesquihydrate, C26H29N2O+·Br−·1.5H2O, (II), were determined.

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“…The search for chiral molecules remains one of the key challenges in modern chemistry . We have previously found that, owing to their length, the 1,6-(3-hexendiyl) bridges adopt a helical turn in diansa [6]-metallocenes .…”

Section: Introductionmentioning

confidence: 99%

E/ZSwitchable Ring-Closing Metathesis in 1,1′-Bis(but-3-enyl)ferrocenes: Synthesis and Characterization of Axially Chiralansa[6]-Ferrocenes

et al. 2022

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A series of ansa[6]-ferrocenes were obtained through the ruthenium-catalyzed ring-closing olefin metathesis in 1,1′-bis(but-3enyl)ferrocenes. The stereoselectivity of this reaction depended on the structure of substrates, that is, mixtures of (E) and (Z) isomers were obtained for alkyl-substituted 3a−3d while (Z)-isomers only for arylsubstituted 3e and 3f. The ansa[6]-ferrocenes are axially chiral in the solid state according to single-crystal X-ray analysis. In the case of methyl-substituted derivative 4a, spontaneous resolution of the racemate was observed during crystallization. The solution properties of (E) and (Z) isomers are remarkably different; the latter displays inequivalence of the two formally identical parts of the molecule at low temperature.

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Enantioselective synthesis of ammonium cations

Cited by 44 publications

References 53 publications

Chirality in Organic and Mineral Systems: A Review of Reactivity and Alteration Processes Relevant to Prebiotic Chemistry and Life Detection Missions

Chirality in Organic and Mineral Systems: A Review of Reactivity and Alteration Processes Relevant to Prebiotic Chemistry and Life Detection Missions

Crystal structures of anhydrous and hydrated N-benzylcinchonidinium bromide

E/ZSwitchable Ring-Closing Metathesis in 1,1′-Bis(but-3-enyl)ferrocenes: Synthesis and Characterization of Axially Chiralansa[6]-Ferrocenes

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