Video Experimental Relacionado

Updated: Dec 1, 2025

Preparation of 6-aminocyclohepta-2,4-dien-1-one Derivatives via Tricarbonyltroponeiron

Preparation of 6-aminocyclohepta-2,4-dien-1-one Derivatives via Tricarbonyltroponeiron

Published on: August 12, 2019

La adición enantioselectiva de 1,3-dienos catalizados por el hierro proporciona ciclooctadienos quirales

Elena Braconi¹, Alissa C Götzinger¹, Nicolai Cramer¹

¹Laboratory of Asymmetric Catalysis and Synthesis, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland.

Journal of the American Chemical Society

|November 11, 2020

Resumen

Los investigadores desarrollaron un nuevo método catalizado por hierro para crear cicloctadienos quirales. Esta síntesis asimétrica eficiente proporciona acceso a compuestos valiosos para la catálisis y la síntesis de productos naturales.

Área de la Ciencia:

Química orgánica
Catálisis asimétrica

Sus antecedentes:

Los ciclooctadienos quirales son andamios importantes en productos naturales y productos químicos especiales.
Su uso como ligandos en la catálisis asimétrica es significativo.
La síntesis asimétrica eficiente de cicloctadienos sustituidos sigue siendo un desafío.

Objetivo del estudio:

Desarrollar un método asimétrico eficiente para la síntesis de ciclooctadienos sustituidos.
Para utilizar la catálisis del hierro para las reacciones de adición cruzada enantioselectiva.

Principales métodos:

Empleando un complejo quiral de hierro α-diamina muy personalizado.
Utilizando la adición cruzada enantioselectiva[4+4] catalizada por el hierro de 1,3-dienos.
Investigar los factores estéricos de los complejos de hierro para comprender la selectividad.

Principales resultados:

Se logra la formación de ciclooctadienos sustituidos en condiciones suaves.
Se ha demostrado una excelente selectividad cruzada y una enantiselectividad muy alta.
Se obtienen cicloctadienos novedosos y funcionalizados con altos rendimientos y enantioselectividades.

Conclusiones:

El método desarrollado catalizado por hierro proporciona un acceso rápido y económico a los ciclooctadienos quirales.
El complejo quiral de hierro α-diimina adaptado es crucial para el éxito de la reacción.
Este método supera los desafíos anteriores en la síntesis asimétrica de estos valiosos compuestos.

Más Videos Relacionados

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

Chemoselective Preparation of 1-Iodoalkynes, 1,2-Diiodoalkenes, and 1,1,2-Triiodoalkenes Based on the Oxidative Iodination of Terminal Alkynes

Chemoselective Preparation of 1-Iodoalkynes, 1,2-Diiodoalkenes, and 1,1,2-Triiodoalkenes Based on the Oxidative Iodination of Terminal Alkynes

Published on: September 12, 2018

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.

Diels–Alder Reaction Forming Cyclic Products: Stereochemistry

Diels–Alder Reaction Forming Cyclic Products: Stereochemistry

The Diels–Alder reaction is one of the robust methods for synthesizing unsaturated six-membered rings. The reaction involves a concerted cyclic movement of six π electrons: four π electrons from the diene and two π electrons from the dienophile.

Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry

Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry

Diels–Alder reactions between cyclic dienes locked in an s-cis configuration and dienophiles yield bridged bicyclic products.

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.

Thermal Electrocyclic Reactions: Stereochemistry

Thermal Electrocyclic Reactions: Stereochemistry

The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.