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Updated: Jul 14, 2026

Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers
08:51

Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers

Published on: August 18, 2017

CHD3の振動刺激は,塩素原子に対する反応性を優先的に促進するのか?

Shannon Yan1, Yen-Tien Wu, Bailin Zhang

  • 1Institute of Atomic and Molecular Sciences, Academia Sinica, Post Office Box 23-166, Taipei, Taiwan 10617.

Science (New York, N.Y.)
|June 26, 2007
PubMed
まとめ

振動刺激による振動刺激.

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From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding06:44

From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding

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Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex10:52

Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex

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Radical Substitution: Allylic Chlorination01:31

Radical Substitution: Allylic Chlorination

Typically, when alkenes react with halogens at low temperatures, an addition reaction occurs. However, upon increasing the temperature or under reaction conditions that form radicals, providing a low but steady concentration of halogen radicals, allylic substitution reaction is favored. This is because allylic hydrogens are very reactive as the formed intermediate is resonance stabilized. For example, when propene is treated with chlorine in the gas phase at 400 °C, it undergoes allylic...
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Radical Halogenation: Stereochemistry

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Halogenation to form a new chiral center:
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Halogens are ortho–para directors. They are more electronegative than carbon. Therefore, as ring substituents, they can withdraw electrons through the inductive effect and deactivate the aromatic ring towards electrophilic substitution. Halogens also have an electron-donating resonance effect on the ring, which influences the orientation of the incoming electrophile. If an electrophile attacks at the ortho or the para position, the halogen donates electrons and stabilizes the intermediate...
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All ortho–para directors, excluding halogens, are activating groups. These groups donate electrons to the ring, making the ring carbons electron-rich. Consequently, the reactivity of the aromatic ring towards electrophilic substitution increases. For instance, the nitration of anisole is about 10,000 times faster than the nitration of benzene. The electron-donating effect of the methoxy group in anisole activates the ortho and para positions on the ring and stabilizes the corresponding...
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Chlorination and bromination are important classes of electrophilic aromatic substitutions, where benzene reacts with chlorine or bromine in the presence of a Lewis acid catalyst to give halogenated substitution products. A Lewis acid such as aluminium chloride or ferric chloride catalyzes the chlorination, and ferric bromide catalyzes the bromination reactions. During the bromination of alkenes, bromine polarizes and becomes electrophilic. However, in the bromination of benzene, the bromine...
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Radical Substitution: Halogenation of Alkanes and Alkyl Substituents

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