JoVE - Journal of Visualized Experiments
JoVE Visualize
Contact Us
このページは機械翻訳されています。他のページは英語で表示される場合があります。 View in English

ピリジンからのπ相互作用による陽子伝達は,カルバニオンとの複合体におけるCO2の伝導を容易にする経路を提供する.

  • 0Davenport Chemistry Laboratories, Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada.
Journal of the American Chemical Society +

|

2024年1月4日

PubMedで要約を見る

まとめ

この要約は機械生成です。

関連する概念動画

Carbocations 02:10

11.3K

Carbocations are one of the reaction intermediates formed during several nucleophilic substitutions or elimination reactions. A carbocation is an electron-deficient species with the central carbon atom having six electrons and three bonded atoms. The central carbon in a carbocation is sp2 hybridized with trigonal planar geometry. It has an empty p orbital perpendicular to the plane of the structure that can accept electrons. Thus, carbocations act as strong electrophiles and may react with any...

Vicinal Diols via Reductive Coupling of Aldehydes or Ketones: Pinacol Coupling Overview 01:27

1.8K

Wilhelm Rudolph Fittig discovered the pinacol coupling reaction in 1859. It is a radical dimerization reaction and involves the reductive coupling of aldehydes or ketones in the presence of hydrocarbon solvent to yield vicinal diols.

The radical reaction is initiated by a single electron transfer from metals like sodium and magnesium to a spin-paired molecule like aldehydes or ketones to generate a ketyl—a radical anion. The ketyl has a radical character on the carbon atom and a charge...

¹H NMR: Long-Range Coupling 01:27

1.8K

The coupling interactions of nuclei across four or more bonds are usually weak, with J values less than 1 Hz. While these are usually not observed in spectra, the presence of multiple bonds along the coupling pathway can result in observable long-range coupling.
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene...

Basicity of Heterocyclic Aromatic Amines 01:25

6.0K

Heterocyclic amines, where the N atom is a part of an alicyclic system, are similar in basicity to alkylamines. Interestingly, the heterocyclic amine having a nitrogen atom as part of an aromatic ring has much less basicity than its corresponding alicyclic counterpart. For this reason, as presented in Figure 1, piperidine (pKb = 2.8) is significantly more basic than pyridine (pKb = 8.8).

Figure 1. The comparison of the basicity of piperidine and pyridine.
This difference in basicity may be...

Photochemical Electrocyclic Reactions: Stereochemistry 01:26

1.8K

The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation

[3,3] Sigmatropic Rearrangement of 1,5-Dienes: Cope Rearrangement 01:21

2.7K

The Cope rearrangement is classified as a [3,3] sigmatropic shift in 1,5-dienes, leading to a more stable, isomeric 1,5-diene. The reaction involves a concerted movement of six electrons, four from two π bonds and two from a σ bond, via an energetically favorable chair-like transition state.

From a molecular orbital perspective, the rearrangement can be viewed as the interaction between the ground state frontier orbitals of the allyl anion and cation. Under thermal conditions, the...