Video Experimental Relacionado
Updated: Jul 11, 2026
04:38
Preparation of Contiguous Bisaziridines for Regioselective Ring-Opening Reactions
Published on: July 28, 2022
Benzimidazol y ligandos relacionados para la cicloadición azida-alquina catalizada por Cu
Valentin O Rodionov1, Stanislav I Presolski, Sean Gardinier
1Department of Chemistry and The Skaggs Institute of Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
Journal of the American Chemical Society
|October 5, 2007
Resumen
Las tris ((2-benzimidazolilmetil) aminas son ligandos superiores para la cicloadición azida-alquina catalizada por el cobre ((I). Un ligando soluble en agua, (BimC4A) 3, permite una síntesis rápida y de alto rendimiento de triazoles funcionalizados utilizando un mínimo catalizador de cobre.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- La catálisis de la catálisis.
- Química Medicinal La Química Medicinal es un campo de estudio de la química medicinal.
Sus antecedentes:
- La cicloadición azida-alquina catalizada por cobre (CuAAC) es una reacción química de "clic" vital.
- El diseño de ligandos es crucial para optimizar la eficiencia y el alcance del catalizador CuAAC.
- Las aminas tris ((2-benzimidazolilmetil) representan una clase prometedora de ligandos para CuAAC.
Objetivo del estudio:
- Evaluar las aminas tris(2-benzimidazolilmetil) y los ligandos relacionados como aceleradores para CuAAC.
- Para investigar la influencia de la estructura del ligando en la actividad catalítica.
- Identificar las condiciones óptimas para la síntesis rápida y de alto rendimiento de triazol.
Principales métodos:
- Mediciones de velocidad absoluta utilizando cinética de apagado de alicuota.
- Mediciones de velocidad relativa utilizando calorimetría de reacción.
- Síntesis y evaluación de varios benzimidazol, benzothiazol y piridil ligandos.
Principales resultados:
- Las aminas tris ((2-benzimidazolilmetil) demostraron una aceleración superior del CuAAC.
- Los ligandos con brazos colgantes de alquilcarboxilato fueron ventajosos en condiciones de concentración.
- El sistema catalizador exhibió un comportamiento complejo con respecto al pH y las sales de amortiguación.
- Se mantuvieron altas tasas catalíticas incluso con altas concentraciones de ligandos.
- (BimC4A) 3, un ligando soluble en agua, facilitó la síntesis eficiente de triazol con 0,01-0,5 mol % Cu.
Conclusiones:
- Las Tris ((2-benzimidazolilmetil) aminas son ligandos muy efectivos para las reacciones CuAAC.
- El ligando hidrosoluble (BimC4A) 3 ofrece una ruta conveniente y eficiente a los triazoles funcionalizados.
- Este sistema catalítico es adecuado para una síntesis rápida y de alto rendimiento con baja carga de catalizador.
Más Videos Relacionados
Videos de Conceptos Relacionados
01:22Preparation of 1° Amines: Azide Synthesis
Direct alkylation of ammonia produces polyalkylated amines, along with a quaternary ammonium salt. To exclusively prepare primary amines, the azide synthesis method can be used.
Azide ions act as good nucleophiles and react with unhindered alkyl halides to form alkyl azides. Alkyl azides do not participate in further nucleophilic substitution reactions, thereby eliminating the chances of polyalkylated products. Alkyl azides are reduced by hydride-based reducing agents, like lithium aluminum...
Azide ions act as good nucleophiles and react with unhindered alkyl halides to form alkyl azides. Alkyl azides do not participate in further nucleophilic substitution reactions, thereby eliminating the chances of polyalkylated products. Alkyl azides are reduced by hydride-based reducing agents, like lithium aluminum...
01:20Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
Arenediazonium substitution reactions occur when the diazonium group is substituted by various functional groups such as halides, hydroxyl, nitrile, etc. For instance, arenediazonium salts react with copper(I) salts of chloride, bromide, or cyanide to form corresponding aryl chlorides, bromides, and nitriles. These reactions are named Sandmeyer reactions. Although the mechanism of this reaction is complicated, as illustrated in Figure 1, they are believed to progress via an aryl copper...
01:11Nucleophilic Aromatic Substitution: Elimination–Addition
Simple aryl halides do not react with nucleophiles. However, nucleophilic aromatic substitutions can be forced under certain conditions, such as high temperatures or strong bases. The mechanism of substitution under such conditions involves the highly unstable and reactive benzyne intermediate. Benzyne contains equivalent carbon centers at both ends of the triple bond, each of which is equally susceptible to nucleophilic attack. This 50–50 distribution of products is confirmed through isotopic...
01:14Nucleophilic Aromatic Substitution of Aryldiazonium Salts: Aromatic SN1
Treating arylamines with nitrous acid gives aryldiazonium salts that are effective substrates in nucleophilic aromatic substitution reactions. The diazonio group in these salts can be easily displaced by different nucleophiles, yielding a wide variety of substituted benzenes. The leaving group departs as nitrogen gas, and this easy elimination is the driving force for the substitution reaction.
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo, or cyano...
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo, or cyano...
01:11Aryldiazonium Salts to Azo Dyes: Diazo Coupling
The reaction of weakly electrophilic aryldiazonium (also called arenediazonium) salts with highly activated aromatic compounds leads to the formation of products with an —N=N— link, called an azo linkage. This reaction, presented in Figure 1, is known as diazo coupling and occurs without the loss of the nitrogen atoms of the aryldiazonium salt. Highly activated aromatic compounds such as phenols or arylamines favor the diazo coupling reaction. The coupling generally occurs at the para position.
01:16Cycloaddition 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.