Organic Chemistry And Reaction Mechanisms Codexery

Atropisomer

Stereoisomers arising from hindered rotation about a single bond.

Last updated

Atropisomer

User:Calmkelp · Public domain

Atropisomers are stereoisomers that arise from hindered rotation about a single bond, allowing individual rotamers to be isolated.[1] They exhibit axial chirality and can be either enantiomers or diastereomers depending on the substituents.[1] Repulsive interactions that block rotation are what give individual atropisomers their stability.[2]

Quick Facts

Field
Stereochemistry
Known for
Axial chirality due to hindered rotation about a single bond
Refined definition by
Michinori Ōki

Facts from the source article.

Key facts and history

The word atropisomer was coined by German biochemist Richard Kuhn in 1933 for Karl Freudenberg's Stereochemie volume.[3] Michinori Ōki refined the definition, specifying that atropisomers interconvert with a half-life of at least 1000 seconds at a given temperature.[3] Determining axial stereochemistry of biaryl atropisomers can be done using a Newman projection along the hindered rotation axis.[4] The absolute configuration is assigned P or Δ for clockwise and M or Λ for counterclockwise.[4]

In 1922, George Christie and James Kenner were the first to experimentally observe atropisomerism, doing so in a tetra substituted biphenyl diacid.[3] Biphenyl derivatives and analogues constitute the majority of atropisomerism examples.[5] Partial double bond character in C-N bonds causes some acylic systems, including amides and thioamides, to also display this phenomenon.[5] Dynamic nuclear magnetic resonance spectroscopy is a common technique for investigating atropisomerism.[2]

Atropisomer
Atropisomer. Image: Roland Mattern · Public domain · Wikimedia Commons

Seed-directed crystallization of racemates is a method for isolating individual atropisomers.[6]

What the research sources say

The 2005 Angewandte Chemie International Edition paper by Bringmann et al. is titled "Atroposelective Synthesis of Axially Chiral Biaryl Compounds".[7] The 2012 work by Alkorta et al., published in Advances in Heterocyclic Chemistry, is titled "Atropisomerism and Axial Chirality in Heteroaromatic Compounds".[8][9] Clayden et al. published a 2009 paper in Angewandte Chemie International Edition titled "The Challenge of Atropisomerism in Drug Discovery".[10] Prost and Thormann's 2003 Electrophoresis paper assesses the stereoselective metabolism of methaqualone, a drug example of atropisomerism.[11][12]

The 2024 Wiley eBook is titled "Atropisomerism in Asymmetric Organic Synthesis".[13][14]

References

  1. Wikipedia, "Atropisomer" (CC BY-SA 4.0), which cites: Bringmann, "Atroposelective Synthesis of Axially Chiral Biaryl Compounds", Angewandte Chemie International Edition, 2005, p. 5384–5427; Anslyn, Eric V., "Modern physical organic chemistry", University Science Books, 2006; Clayden, "The Challenge of Atropisomerism in Drug Discovery", Angew. Chem. Int. Ed., 2009, p. 6398–6401; Bringmann, "Atroposelective Synthesis of Axially Chiral Biaryl Compounds", Angewandte Chemie International Edition, 2005, p. 5384–5427 (we also read that source) en.wikipedia.org
  2. Wikipedia, "Atropisomer" (CC BY-SA 4.0), which cites: Bringmann, "Atroposelective Synthesis of Axially Chiral Biaryl Compounds", Angewandte Chemie International Edition, 2005, p. 5384–5427; Alkorta, "Atropisomerism and Axial Chirality in Heteroaromatic Compounds", 2012, p. 1–188; Alkorta, "Atropisomerism and Axial Chirality in Heteroaromatic Compounds", 2012, p. 1–188; LaPlante, "Revealing Atropisomer Axial Chirality in Drug Discovery", ChemMedChem, 2011, p. 505–513 (we also read that source) en.wikipedia.org
  3. Wikipedia, "Atropisomer" (CC BY-SA 4.0), which cites: Kuhn Richard, "Stereochemie (Karl Freudenberg, Ed.)", Leipzig-Wien:Franz-Deutike, 1933, p. 803–824; Christie, "LXXI.—The molecular configurations of polynuclear aromatic compounds. Part I. The resolution of γ-6 : 6′-dinitro- and 4 : 6 : 4′ : 6′-tetranitro-diphenic acids into optically active components", Journal of the; Ōki, "Topics in Stereochemistry", 2007, p. 1–81; Alkorta, "Atropisomerism and Axial Chirality in Heteroaromatic Compounds", 2012, p. 1–188 (we also read that source) en.wikipedia.org
  4. Wikipedia, "Atropisomer" (CC BY-SA 4.0), which cites: ; Bringmann, "Atroposelective Synthesis of Axially Chiral Biaryl Compounds", Angewandte Chemie International Edition, 2005, p. 5384–5427 (we also read that source) en.wikipedia.org
  5. Wikipedia, "Atropisomer" (CC BY-SA 4.0) en.wikipedia.org
  6. Wikipedia, "Atropisomer" (CC BY-SA 4.0), which cites: Wilson, "Thermally induced resolution of racemic 1,1'-binaphthyl in the solid state", Journal of the American Chemical Society, 1975-03-01, p. 1474–1478; Einhorn, "Solid-State Isomerization of Atropodiastereomers: Effective Diastereoselection through Polymorphic Transformations", Angewandte Chemie International Edition, 2001, p. 1926–1929; Pu, "1,1'-Binaphthyl Dimers, Oligomers, and Polymers: Molecular Recognition, Asymmetric Catalysis, and New Materials", Chemical Reviews, 1998-11-05, p. 2405–2494 (original not read by us) en.wikipedia.org
  7. Gerhard Bringmann, "Atroposelective Synthesis of Axially Chiral Biaryl Compounds", Angewandte Chemie International Edition (2005), doi:10.1002/anie.200462661. OpenAlex metadata CC0; paper not read. doi.org
  8. Ibón Alkorta, "Atropisomerism and Axial Chirality in Heteroaromatic Compounds", Advances in heterocyclic chemistry (2012), doi:10.1016/b978-0-12-396530-1.00001-2. OpenAlex metadata CC0; paper not read. doi.org
  9. Open Library record, ISBN 9780123965301 ("Advances in heterocyclic chemistry"). CC0 (metadata); book content not read. openlibrary.org
  10. Jonathan Clayden, "The Challenge of Atropisomerism in Drug Discovery", Angewandte Chemie International Edition (2009), doi:10.1002/anie.200901719. OpenAlex metadata CC0; paper not read. doi.org
  11. Francine Prost, "Assessment of the stereoselective metabolism of methaqualone in man by capillary electrophoresis", Electrophoresis (2003), doi:10.1002/elps.200305512. OpenAlex metadata CC0; paper not read. doi.org
  12. Wikipedia, "Atropisomer" (CC BY-SA 4.0), which cites: Prost, "Assessment of the stereoselective metabolism of methaqualone in man by capillary electrophoresis", Electrophoresis, 2003, p. 2598–2607; "Atropisomerism in Asymmetric Organic Synthesis: Challenges and Applications", Wiley, 2024-11-12 (we also read that source) en.wikipedia.org
  13. , "Atropisomerism in Asymmetric Organic Synthesis", Wiley eBooks (2024), doi:10.1002/9783527844258. OpenAlex metadata CC0; paper not read. doi.org
  14. Open Library record, ISBN 9783527352838 ("Atropisomerism in Asymmetric Organic Synthesis - Challenges and Applications"). CC0 (metadata); book content not read. openlibrary.org

Each numbered sentence above was checked against the source it cites before publication. Sentences citing Wikipedia adapt text from the English Wikipedia article Atropisomer (contributors), used under CC BY-SA 4.0; this entry is available under the same licence. Other sources were used for facts only; no text or images are copied from them.

More in Organic Chemistry And Reaction Mechanisms

Cahn–Ingold–Prelog priority rulesChirality (chemistry)Cis–trans isomerismConvergent synthesisCycloadditionDiels–Alder reactionDiastereomerDivergent synthesisE1cB-elimination reactionEi mechanismElectrophilic additionElectrophilic substitution

Sources

Compiled from Wikipedia and the sources listed below. Text from Wikipedia is available under CC BY-SA 4.0; this entry is adapted from it.

Spotted an error? Know more?

Reader corrections go straight into our review queue. Suggest an edit · How this site is sourced

Comments

Loading…
Open in the interactive codex →