Video Experimental Relacionado

Updated: Feb 4, 2026

Qualitative Identification of Carboxylic Acids, Boronic Acids, and Amines Using Cruciform Fluorophores

Qualitative Identification of Carboxylic Acids, Boronic Acids, and Amines Using Cruciform Fluorophores

Published on: August 19, 2013

Acoplamiento oxidativo enantioselectivo de ácidos carboxílicos a aldehídos alfa ramificados

Lars A Leth¹, Line Næsborg¹, Gabriel J Reyes-Rodríguez¹

¹Department of Chemistry , Aarhus University , DK-8000 Aarhus C , Denmark.

Journal of the American Chemical Society

|September 25, 2018

Resumen

Este estudio introduce un nuevo método de organocatálisis para el acoplamiento de ácidos carboxílicos con aldehídos alfa ramificados. La reacción enantioselectiva logra altos rendimientos y enantioselectividades, expandiendo las posibilidades sintéticas en la catálisis.

Área de la Ciencia:

Química orgánica
Catálisis
Metodología sintética

Sus antecedentes:

La organocatálisis es un campo en crecimiento para la síntesis química sostenible.
Las reacciones de acoplamiento son fundamentales en la construcción de moléculas orgánicas complejas.
La síntesis enantioselectiva es crucial para los productos farmacéuticos y los productos químicos finos.

Objetivo del estudio:

Desarrollar un nuevo método organocatalítico para el acoplamiento de ácidos carboxílicos a aldehídos alfa ramificados.
Para lograr altos rendimientos y enantioselectividades en esta reacción de acoplamiento.
Para aclarar el papel mecanicista del catalizador de aminas primario.

Principales métodos:

Utilizando la catálisis de aminas primarias en combinación con un oxidante.
Desarrollo de un protocolo de acoplamiento α enantioselectivo.
Emplear estudios experimentales y mecanicistas para comprender la vía de reacción.

Principales resultados:

Acoplamiento exitoso de ácidos carboxílicos aromáticos y alifáticos a aldehídos alfa ramificados.
Se obtienen altos rendimientos de hasta el 97%.
Se obtienen buenas enantioselectividades de hasta el 92% ee para la mayoría de los sustratos.

Conclusiones:

Se ha establecido una nueva reactividad en la organocatálisis.
La metodología proporciona una ruta eficiente para el acoplamiento α enantioselectivo.
El catalizador de amina primaria juega un papel clave en el mecanismo de reacción.

Más Videos Relacionados

Development of Heterogeneous Enantioselective Catalysts using Chiral Metal-Organic Frameworks MOFs

Development of Heterogeneous Enantioselective Catalysts using Chiral Metal-Organic Frameworks MOFs

Published on: January 17, 2020

Green and Low-cost Production of Thermally Stable and Carboxylated Cellulose Nanocrystals and Nanofibrils Using Highly Recyclable Dicarboxylic Acids

Green and Low-cost Production of Thermally Stable and Carboxylated Cellulose Nanocrystals and Nanofibrils Using Highly Recyclable Dicarboxylic Acids

Published on: January 9, 2017

Videos de Conceptos Relacionados

Oxidations of Aldehydes and Ketones to Carboxylic Acids

Oxidations of Aldehydes and Ketones to Carboxylic Acids

Oxidation of aldehydes and ketones results in the formation of carboxylic acids. Aldehydes, bearing hydrogen next to the carbonyl group, are easily oxidized compared to ketones. This is because an aldehydic proton can easily be abstracted during oxidation.
Aldehydes readily undergo oxidation in strong oxidizing agents such as potassium permanganate and chromic acid. The oxidation can also be carried out using mild oxidizing agents such as silver oxide. In fact, aldehydes can be easily oxidized...

Acid-Catalyzed α-Halogenation of Aldehydes and Ketones

Acid-Catalyzed α-Halogenation of Aldehydes and Ketones

By replacing an α-hydrogen with a halogen, acid-catalyzed α-halogenation of aldehydes or ketones yields a monohalogenated product
In the first step of the mechanism, the acid protonates the carbonyl oxygen resulting in a resonance-stabilized cation, which subsequently loses an α-hydrogen to form an enol tautomer. The C=C bond in an enol is highly nucleophilic because of the electron-donating nature of the –OH group. Consequently, the double bond attacks an electrophilic halogen to form a...

α-Halogenation of Carboxylic Acid Derivatives: Overview

α-Halogenation of Carboxylic Acid Derivatives: Overview

Unlike aldehydes and ketones, carboxylic acids do not readily participate in α halogenation reactions via enols or enolate intermediates. However, α-halogenated acids are obtained through other methods. One of the approaches is the Hell–Volhard–Zelinsky (HVZ) reaction, wherein the carboxylic acid is treated with halogen in the presence of PBr3. It involves the conversion of acid to acid halide, which exists in equilibrium with its enol form. The enol attacks the...

Alkynes to Carboxylic Acids: Oxidative Cleavage

Alkynes to Carboxylic Acids: Oxidative Cleavage

Alkynes undergo oxidative cleavage in the presence of oxidizing reagents like potassium permanganate and ozone. The triple bond — one σ bond and two π bonds — is completely cleaved, and the alkyne is oxidized to carboxylic acids. When warm and basic aqueous potassium permanganate is used as an oxidizing agent, alkynes are first converted to carboxylate salts via an unstable α-diketone intermediate. Further, a mild acid treatment protonates the carboxylate anions...

Preparation of Aldehydes and Ketones from Nitriles and Carboxylic Acids

Preparation of Aldehydes and Ketones from Nitriles and Carboxylic Acids

Although it is possible to reduce a carboxylic acid to an aldehyde, strong reducing agents, like lithium aluminum hydride (LAH), prohibit a controlled reduction, instead causing the generated aldehyde to instantly over-reduce to a primary alcohol.
Reducing carboxylic acid derivatives like acyl chlorides (RCOCl), esters (RCO2R′), and nitriles (RCN) using milder aluminum hydride agents like lithium tri-tert-butoxyaluminum hydride [LiAlH(O-t-Bu)3] and diisobutylaluminum hydride [DIBAL-H]...

Preparation of Aldehydes and Ketones from Carboxylic Acid Derivatives

Preparation of Aldehydes and Ketones from Carboxylic Acid Derivatives

Aldehydes are more reactive than carboxylic acids and hence, can get over-reduced to alcohol in the presence of strong reducing agents. Therefore, carboxylic acids are inefficient in preparing aldehydes using LAH.
Carboxylic acid derivatives like acid chlorides and esters are more easily reducible than the corresponding acids. The derivatives reduce in the presence of mild reducing agents to give aldehydes. Aldehydes can also be prepared by Rosenmund reduction, that is, the reduction of...