Video Experimental Relacionado

Updated: Apr 7, 2026

Preparation of a Corannulene-functionalized Hexahelicene by CopperI-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units

Preparation of a Corannulene-functionalized Hexahelicene by CopperI-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units

Published on: September 18, 2016

Una adición catalitica asimétrica intramolecular [4 + 1]-ciclo para la síntesis total de productos naturales de

Wen Xiu¹, Calvin D Huffman¹, William A Swann¹

¹Department of Chemistry, Purdue University, West Lafayette 47907, Indiana, United States.

Journal of the American Chemical Society

|May 12, 2025

Resumen

Una nueva reacción catalizada por níquel permite la adición cíclica [4 + 1] intramolecular asimétrica, creando marcos complejos [4.3.0]-azabicíclicos. Este método es valioso para sintetizar varios productos naturales policíclicos.

Área de la Ciencia:

Química orgánica
Química sintética
Catálisis

Sus antecedentes:

Las reacciones intramoleculares de Diels-Alder son clave para sintetizar productos naturales policíclicos con anillos de seis miembros.
La analogía [4 + 1]-cicloadición ofrece potencial para los marcos [n.3.0]-bicíclicos, pero carece de métodos establecidos para la síntesis de productos naturales.

Objetivo del estudio:

Desarrollar un método viable para la adición intramolecular asimétrica [4 + 1]-ciclo adecuado para la síntesis de productos naturales.
Utilizar un enfoque catalizado por níquel para la construcción de productos [4.3.0]-azabicíclicos.

Principales métodos:

Utilizando una reacción asimétrica intramolecular [4 + 1]-cicloadición catalizada por níquel.
Generación de un intermediario clave de vinilideno por reducción a partir de un precursor de 1,1-dicloroalqueno.
Utilizando modelos DFT para dilucidar el mecanismo de reacción que involucra [2 + 2]-cicloadición, 1,3-migración y eliminación reductiva.

Principales resultados:

Formación exitosa de un producto [4.3.0]-azabicíclico a través de la nueva cicloadición.
El conducto de carga contiene alquenos tri y tetrasubstituidos estéricamente diferenciados.
La funcionalización selectiva de los alquenos permite la síntesis divergente de múltiples productos naturales.

Conclusiones:

La reacción catalizada por níquel desarrollada proporciona una poderosa nueva estrategia para acceder a estructuras policíclicas complejas.
Este método mejora significativamente el conjunto de herramientas sintéticas para la síntesis de productos naturales.
El enfoque permite la preparación eficiente de diversos productos naturales, incluidos los análogos de la incarvilina y la tecostanina.

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

Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions

Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions

Published on: July 17, 2020

Videos de Conceptos Relacionados

Reduction of Alkenes: Asymmetric Catalytic Hydrogenation

Reduction of Alkenes: Asymmetric Catalytic Hydrogenation

Catalytic hydrogenation of alkenes is a transition-metal catalyzed reduction of the double bond using molecular hydrogen to give alkanes. The mode of hydrogen addition follows syn stereochemistry.
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...

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.

Alkenes via Reductive Coupling of Aldehydes or Ketones: McMurry Reaction

Alkenes via Reductive Coupling of Aldehydes or Ketones: McMurry Reaction

The radical dimerization of ketones or aldehydes gives vicinal diols through a pinacol coupling reaction. However, the behavior of titanium metals used for the reaction as a source of electrons is unusual. When the reaction is carried out in the presence of titanium, diols can be isolated at low temperatures. Else titanium further reacts with diols, forming alkenes through the McMurry reaction.

Cyclohexenones via Michael Addition and Aldol Condensation: The Robinson Annulation

Cyclohexenones via Michael Addition and Aldol Condensation: The Robinson Annulation

Robinson annulation is a base-catalyzed reaction for the synthesis of 2-cyclohexenone derivatives from 1,3-dicarbonyl donors (such as cyclic diketones, β-ketoesters, or β-diketones) and α,β-unsaturated carbonyl acceptors. Named after Sir Robert Robinson, who discovered it, this reaction yields a six-membered ring with three new C–C bonds (two σ bonds and one π bond).

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.