Video Experimental Relacionado

Updated: Jun 20, 2026

Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones

Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones

Published on: February 7, 2019

[4+2] cicloadición de o-xililenos con iminas utilizando el catalizador de paladio

Satoshi Ueno¹, Masakazu Ohtsubo, Ryoichi Kuwano

¹Department of Chemistry, Graduate School of Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.

Journal of the American Chemical Society

|August 25, 2009

Resumen

Una nueva reacción de cicloadición catalizada por el paladio sintetiza de manera eficiente las tetrahidroisoquinolinas a partir de carbonatos bencílicos e iminas. Los aditivos de fluoruro aceleran significativamente esta reacción, que imita la reacción hetero-Diels-Alder.

Área de la Ciencia:

Química orgánica es la química orgánica.
La catálisis de la catálisis.
Metodología sintética de la metodología sintética.

Sus antecedentes:

Las tetrahidroisoquinolinas son importantes compuestos heterocíclicos con diversas actividades biológicas.
Las rutas sintéticas eficientes para las tetrahidroisoquinolinas sustituidas son muy buscadas en la química medicinal.
Las reacciones catalizadas por el paladio ofrecen herramientas poderosas para construir moléculas orgánicas complejas.

Objetivo del estudio:

Desarrollar una nueva reacción de cicloadición catalizada por paladio para la síntesis de tetrahidroisoquinolina.
Para investigar el mecanismo de la cicloadición catalítica.
Para explorar el efecto de los aditivos en la eficiencia de la reacción.

Principales métodos:

Reacción de cicloadición de carbonatos bencílicos o- ((sililmetilo) con iminas.
Se utilizó un catalizador de paladio específico: Pd(eta(3) -C(3) H(5)) Cp-DPPPent.
Investigó el papel de los aditivos de fluoruro en la aceleración de la velocidad de reacción.

Principales resultados:

Logró buenos a altos rendimientos de tetrahidroisoquinolinas.
Se demostró que los aditivos de fluoruro aumentan significativamente la velocidad de reacción.
Se aclaró un mecanismo que involucra un intermediario de 2-palladaindano, que actúa como un equivalente de o-xileno.

Conclusiones:

El sistema catalítico desarrollado proporciona una ruta eficiente a las tetrahidroisoquinolinas.
El mecanismo de reacción es análogo a la reacción hetero-Diels-Alder de o-xileno con iminas.
Los aditivos de fluoruro son cruciales para mejorar la actividad catalítica.

Más Videos Relacionados

Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions

Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions

Published on: July 30, 2017

Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-(phosphinetriyl)tripiperidine]}palladium Under Mild Reaction Conditions

Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-(phosphinetriyl)tripiperidine]}palladium Under Mild Reaction Conditions

Published on: March 20, 2014

Videos de Conceptos Relacionados

Cycloaddition Reactions: Overview

Cycloaddition Reactions: Overview

Cycloadditions are one of the most valuable and effective synthesis routes to form cyclic compounds. These are concerted pericyclic reactions between two unsaturated compounds resulting in a cyclic product with two new σ bonds formed at the expense of π bonds. The [4 + 2] cycloaddition, known as the Diels–Alder reaction, is the most common. The other example is a [2 + 2] cycloaddition.

[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction

[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction

The Diels–Alder reaction is an example of a thermal pericyclic reaction between a conjugated diene and an alkene or alkyne, commonly referred to as a dienophile. The reaction involves a concerted movement of six π electrons, four from the diene and two from the dienophile, forming an unsaturated six-membered ring. As a result, these reactions are classified as [4+2] cycloadditions.

Cycloaddition Reactions: MO Requirements for Thermal Activation

Cycloaddition Reactions: MO Requirements for Thermal Activation

Thermal cycloadditions are reactions where the source of activation energy needed to initiate the reaction is provided in the form of heat. A typical example of a thermally-allowed cycloaddition is the Diels–Alder reaction, which is a [4 + 2] cycloaddition. In contrast, a [2 + 2] cycloaddition is thermally forbidden.

Electrophilic 1,2- and 1,4-Addition of X2 to 1,3-Butadiene

Electrophilic 1,2- and 1,4-Addition of X₂ to 1,3-Butadiene

Electrophilic addition of halogens to alkenes proceeds via a cyclic halonium ion to form a 1,2-dihalide or a vicinal dihalide.

Aldehydes and Ketones with Amines: Imine Formation Mechanism

Aldehydes and Ketones with Amines: Imine Formation Mechanism

Imine formation involves the addition of carbonyl compounds to a primary amine. It begins with the generation of carbinolamine through a series of steps involving an initial nucleophilic attack and then several proton transfer reactions. The second part includes the elimination of water, as a leaving group, to give the imine.
Imines are formed under mildly acidic conditions. A pH of 4.5 is ideal for the reaction.
If the pH is low or the solution is too acidic, the reaction slows down in the...

Cycloaddition Reactions: MO Requirements for Photochemical Activation

Cycloaddition Reactions: MO Requirements for Photochemical Activation

Some cycloaddition reactions are activated by heat, while others are initiated by light. For example, a [2 + 2] cycloaddition between two ethylene molecules occurs only in the presence of light. It is photochemically allowed but thermally forbidden.