JoVE - Journal of Visualized Experiments
JoVE Visualize
Contact Us
Esta página ha sido traducida por una máquina. Otras páginas pueden seguir apareciendo en inglés. View in English

Montaje rápido de los furanos tetrasubstituidos mediante el reordenamiento de tipo Pummerer

Journal of the American Chemical Society +

|

5 de enero de 2021

|

5 de enero de 2021

Ver abstracta en PubMed

Resumen

Este resumen es generado por máquina.

Un nuevo método sintetiza rápidamente furanos altamente sustituidos utilizando una ciclización oxidativa leve de dihidrotiofenos. Este versátil protocolo de síntesis de furanos ofrece altos rendimientos y permite la construcción de moléculas complejas.

Área De La Ciencia

  • Química orgánica
  • Química Heterocíclica

Sus Antecedentes

  • Existen métodos limitados para la síntesis personalizada de furanos completamente sustituidos.
  • El desarrollo de protocolos eficientes para los furanos tetrasubstituidos es crucial para la síntesis orgánica.

Objetivo Del Estudio

  • Para informar de un nuevo protocolo rápido para la construcción de tetrasubstituidos, funcional ortogonalmente furans.
  • Demostrar la versatilidad de los furanos sintetizados como intermediarios en otras transformaciones químicas.

Principales Métodos

  • Apertura de anillo regioselectivo de los 2,5-dihidrotiofenos.
  • Ciclización oxidativa con N-clorosuccinimida (NCS) bajo condiciones suaves.
  • Estudios mecánicos, incluido el análisis computacional, para elucidar las vías de reacción.

Principales Resultados

  • Se obtienen altos rendimientos de furanos tetrasubstituidos en 30 minutos a temperatura ambiente.
  • Utilidad demostrada de los furanos en varias reacciones postmodificación.
  • Reorganización sin precedentes del tipo Pummerer identificada en el mecanismo de reacción.

Conclusiones

  • El método desarrollado proporciona una vía potente y eficiente para obtener derivados complejos de furanos.
  • Los furanos sintetizados son bloques de construcción versátiles para la síntesis orgánica avanzada.
  • El protocolo fue validado a través de la síntesis total de las pleurotinas A, B y D.

Videos de Conceptos Relacionados

Preparation of 1° Amines: Hofmann and Curtius Rearrangement Overview 01:07

3.4K

In the presence of an aqueous base and a halogen, primary amides can lose the carbonyl (as carbon dioxide) and undergo rearrangement to form primary amines. This reaction, called the Hofmann rearrangement, can produce primary amines (aryl and alkyl) in high yields without contamination by secondary and tertiary amines.

In the Curtius rearrangement, acyl azides are converted into primary amines under thermal conditions, accompanied by the loss of gaseous N2 and CO2. The loss of nitrogen acts as...

Preparation of 1° Amines: Hofmann and Curtius Rearrangement Mechanism 01:26

3.8K

The Hofmann and Curtius rearrangement reactions can be applied to synthesize primary amines from carboxylic acid derivatives such as amides and acyl azides. In the Hofmann rearrangement, a primary amide undergoes deprotonation in the presence of a base, followed by halogenation to generate an N-haloamide. A second proton abstraction produces a stabilized anionic species, which rearranges to an isocyanate intermediate via an alkyl group migration from the carbonyl carbon to the neighboring...

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

3.1K

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 two π...

Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions 01:20

2.2K

Arenediazonium substitution reactions occur when the diazonium group is substituted by various functional groups such as halides, hydroxyl, nitrile, etc. For instance, arenediazonium salts react with copper(I) salts of chloride, bromide, or cyanide to form corresponding aryl chlorides, bromides, and nitriles. These reactions are named Sandmeyer reactions. Although the mechanism of this reaction is complicated, as illustrated in Figure 1, they are believed to progress via an aryl copper...

[3,3] Sigmatropic Rearrangement of Allyl Vinyl Ethers: Claisen Rearrangement 01:24

2.5K

The Claisen rearrangement is a [3,3] sigmatropic rearrangement of allyl vinyl ethers to unsaturated carbonyl compounds. The rearrangement is a concerted pericyclic reaction proceeding via a chair-like transition state.

An aromatic Claisen rearrangement involves the conversion of allyl aryl ethers to an unstable ketone intermediate, which tautomerizes to give ortho-substituted phenols.

However, ortho-substituted allyl aryl ethers exclusively yield para-substituted phenols via two sequential...

Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene 01:13

7.0K

Bromination and chlorination of aromatic rings by electrophilic aromatic substitution reactions are easily achieved, but fluorination and iodination are difficult to achieve. Fluorine is so reactive that its reaction with benzene is difficult to control, resulting in poor yields of monofluoroaromatic products. To address this, Selectfluor reagent is used as a fluorine source in which a fluorine atom is bonded to a positively charged nitrogen.

Unlike fluorine, iodine is highly unreactive for...