Reacciones de alquilo-alquilo Suzuki dirigidas por aminas estereoconvergentes de cloruros de alquilo secundarios no activados
Video Experimental Relacionado
Updated: Jun 2, 2026
08:12
A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species
Published on: August 16, 2018
Zhe Lu1, Ashraf Wilsily, Gregory C Fu
1Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Journal of the American Chemical Society
|May 11, 2011
Resumen
Los investigadores desarrollaron un nuevo método de acoplamiento cruzado estereoconvergente utilizando cloruros de alquilo no activados en las reacciones de Suzuki. Este enfoque dirigido a la arylamina permite la formación eficiente de enlaces alquilo-alquilo, lo que hace avanzar la catálisis asimétrica.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- La catálisis es la catálisis.
- Metodología sintética de la metodología sintética.
Sus antecedentes:
- Desarrollar reacciones eficientes de acoplamiento cruzado para electrofilos de alquilo no activados sigue siendo un desafío significativo en la síntesis orgánica.
- Los cloruros de alquilo son típicamente electrófilos menos reactivos, lo que limita su utilidad en las reacciones de acoplamiento cruzado.
- Los métodos estereoconvergentes son cruciales para el control de la estereoquímica en la síntesis de moléculas complejas.
Objetivo del estudio:
- Desarrollar una nueva reacción de acoplamiento cruzado estereoconvergente para electrófilos de alquilo secundarios no activados.
- Investigar el uso de cloruros de alquilo como sustratos en las reacciones de alquilo-alquilo Suzuki dirigidas por arylamina.
- Para aclarar el mecanismo y determinar los factores clave que controlan la enantioselectividad.
Principales métodos:
- Desarrollo de un nuevo sistema catalítico para el acoplamiento cruzado asimétrico alquilo-alquilo Suzuki.
- Utilizando grupos de dirección de arylamina para activar cloruros de alquilo secundarios no activados.
- La realización de estudios de estructura-enantioselectividad para sondear las interacciones catalizador-sustrato.
- Estudios cinéticos para determinar la ley de la tasa e identificar el paso que limita el volumen de negocios.
Principales resultados:
- Se desarrolló con éxito una nueva familia de reacciones de acoplamiento cruzado de alquilo-alquilo Suzuki estereoconvergentes.
- Este método es eficaz para los cloruros de alquilo secundarios no activados, lo que representa una primicia en esta área.
- Los estudios de estructura-enantioselectividad indicaron que el nitrógeno arilamina es el sitio de coordinación primario del catalizador.
- La ley de la tasa determinada apoya la transmitación como la etapa que limita el volumen de negocios en el ciclo catalítico.
Conclusiones:
- La reacción de alquilo-alquilo Suzuki dirigida por arylamina desarrollada proporciona un poderoso nuevo método para el acoplamiento cruzado estereoconvergente de cloruros de alquilo no activados.
- Los hallazgos ofrecen información valiosa sobre el mecanismo del acoplamiento cruzado asimétrico, destacando el papel del grupo de dirección y la etapa de determinación de la tasa.
- Este trabajo amplía el alcance de la química de acoplamiento cruzado y proporciona una base para el futuro desarrollo de catalizadores y aplicaciones sintéticas.
Videos de Conceptos Relacionados
02:48Conversion of Alcohols to Alkyl Halides
This lesson delves into the conversion of alcohols to corresponding alkyl halides and the mechanism of action for different reagents. Typically, the hydroxyl group is first protonated to convert it to a stable leaving group. Consequently, based on the starting alcohol, the mechanism undergoes either of the nucleophilic substitution routes, SN1 or SN2. Tertiary alkyl halides are made using the two-step SN1 mechanism that occurs via a carbocation intermediate, which is stabilized by...
02:26Preparation and Reactions of Sulfides
Sulfides are the sulfur analog of ethers, just as thiols are the sulfur analog of alcohol. Like ethers, sulfides also consist of two hydrocarbon groups bonded to the central sulfur atom. Depending upon the type of groups present, sulfides can be symmetrical or asymmetrical. Symmetrical sulfides can be prepared via an SN2 reaction between 2 equivalents of an alkyl halide and one equivalent of sodium sulfide.
02:27Preparation of Alkynes: Alkylation Reaction
Introduction
Alkylation of terminal alkynes with primary alkyl halides in the presence of a strong base like sodium amide is one of the common methods for the synthesis of longer carbon-chain alkynes. For example, treatment of 1-propyne with sodium amide followed by reaction with ethyl bromide yields 2-pentyne.
Alkylation of terminal alkynes with primary alkyl halides in the presence of a strong base like sodium amide is one of the common methods for the synthesis of longer carbon-chain alkynes. For example, treatment of 1-propyne with sodium amide followed by reaction with ethyl bromide yields 2-pentyne.
01:07Acid Halides to Amides: Aminolysis
Aminolysis is a nucleophilic acyl substitution reaction, where ammonia or amines act as nucleophiles to give the substitution product. Acid halides react with ammonia, primary amines, and secondary amines to yield primary, secondary, and tertiary amides, respectively.
In the first step of the aminolysis mechanism, the amine attacks the carbonyl carbon of the acyl chloride to form a tetrahedral intermediate. In the second step, the carbonyl group is re-formed with the elimination of a chloride...
In the first step of the aminolysis mechanism, the amine attacks the carbonyl carbon of the acyl chloride to form a tetrahedral intermediate. In the second step, the carbonyl group is re-formed with the elimination of a chloride...
01:30Preparation of Amines: Alkylation of Ammonia and Amines
Alkylation is one of the methods used to prepare amines. Direct alkylation of ammonia or a primary amine with an alkyl halide gives polyalkylated amines along with a quaternary ammonium salt through successive SN2 reactions. This process of making the quaternary salt through the direct alkylation method is called exhaustive alkylation.
Each alkylation step makes the nitrogen center more nucleophilic, which triggers successive alkylations until a quaternary ammonium salt is formed. Considering...
Each alkylation step makes the nitrogen center more nucleophilic, which triggers successive alkylations until a quaternary ammonium salt is formed. Considering...
01:38Preparation of Alcohols via Substitution Reactions
Overview
Alcohols can be synthesized from alkyl halides via nucleophilic substitution reactions. The highly polar carbon-halogen bond in the substrate makes halide a good leaving group. The hydroxide ion or water can act as a nucleophile to take the place of halide and form an alcohol. The substitution reactions occur via two different reaction pathways, SN1 or SN2, depending on the nature of carbon attached to the halide.
Primary alcohols are synthesized from primary alkyl halides, and the...
Alcohols can be synthesized from alkyl halides via nucleophilic substitution reactions. The highly polar carbon-halogen bond in the substrate makes halide a good leaving group. The hydroxide ion or water can act as a nucleophile to take the place of halide and form an alcohol. The substitution reactions occur via two different reaction pathways, SN1 or SN2, depending on the nature of carbon attached to the halide.
Primary alcohols are synthesized from primary alkyl halides, and the...