Video Experimental Relacionado
Updated: Jun 12, 2025
12:27
Synthesis of Hypervalent Iodonium Alkynyl Triflates for the Application of Generating Cyanocarbenes
Published on: September 8, 2013
10.8K
Sal de Allenilo Tiantrenio: Un Synthon C3 estable para las reacciones de anulación y acoplamiento cruzado
Srija Tewari1,2, Nicolai Klask1,2, Tobias Ritter1
1Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany.
Journal of the American Chemical Society
|September 24, 2024
Resumen
Los investigadores desarrollaron una sal de alenil sulfonio (ATT) estable para sintetizar diversos heterociclos. Este nuevo reactivo también permite reacciones de acoplamiento cruzado catalizadas por paladio, expandiendo las posibilidades sintéticas en química orgánica.
Área de la Ciencia:
- Química orgánica
- Química sintética
- Química Heterocíclica
Sus antecedentes:
- Las sales de alenil sulfonio son valiosos intermedios sintéticos.
- Las sales de alenil sulfonio anteriores carecían de estabilidad y facilidad de manejo.
- Se necesita el desarrollo de reactivos estables y versátiles de allenil sulfonio.
Objetivo del estudio:
- Síntesis y caracterización de una nueva y estable sal de alenil sulfonio monosubstituida.
- Explorar la utilidad de este reactivo en las reacciones de anulación para la síntesis de heterociclos.
- Investigar su aplicación en reacciones de acoplamiento cruzado catalizadas por paladio.
Principales métodos:
- Síntesis de la sal de alenil sulfonio a partir del tiántreno y el alcohol de propargilo.
- Reacciones de anulación para formar compuestos heterocíclicos.
- Reacciones Suzuki catalizadas por el paladio y acoplamiento reductor.
Principales resultados:
- Se sintetizó con éxito la primera sal monosubstituida de allenilo sulfonio (ATT) estable en el banco y no higroscópica.
- El ATT se utilizó efectivamente en reacciones de anulación para producir varios heterociclos con enlaces dobles exocíclicos, incluidos los derivados de la morfolina, la quinoxalina y la benzodioxepinona.
- ATT demostró utilidad en el acoplamiento cruzado catalizado por paladio, formando enlaces C(sp2) -C(sp2) y C(sp3) -C(sp2).
Conclusiones:
- Se ha desarrollado una nueva sal de allenilo sulfonio (ATT) estable.
- El ATT sirve como un reactivo versátil para sintetizar diversos heterociclos a través de la anulación.
- ATT es la primera sal de allenilo sulfonio capaz de participar en reacciones de acoplamiento cruzado catalizadas por paladio.
Más Videos Relacionados
Videos de Conceptos Relacionados
02:38Electrophilic Addition to Alkynes: Halogenation
8.2K
Introduction
Halogenation is another class of electrophilic addition reactions where a halogen molecule gets added across a π bond. In alkynes, the presence of two π bonds allows for the addition of two equivalents of halogens (bromine or chlorine). The addition of the first halogen molecule forms a trans-dihaloalkene as the major product and the cis isomer as the minor product. Subsequent addition of the second equivalent yields the tetrahalide.
Halogenation is another class of electrophilic addition reactions where a halogen molecule gets added across a π bond. In alkynes, the presence of two π bonds allows for the addition of two equivalents of halogens (bromine or chlorine). The addition of the first halogen molecule forms a trans-dihaloalkene as the major product and the cis isomer as the minor product. Subsequent addition of the second equivalent yields the tetrahalide.
8.2K
02:27Preparation of Alkynes: Alkylation Reaction
10.0K
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.
10.0K
01:14Nucleophilic Aromatic Substitution of Aryldiazonium Salts: Aromatic SN1
2.1K
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,...
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo,...
2.1K
01:20Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
1.9K
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...
1.9K
01:11Aryldiazonium Salts to Azo Dyes: Diazo Coupling
2.9K
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...
2.9K
02:42Acidity of 1-Alkynes
9.6K
The acidic strength of hydrocarbons follows the order: Alkynes > Alkenes > Alkanes. The strength of an acid is commonly expressed in units of pKa — the lower the pKa, the stronger the acid. Among the hydrocarbons, terminal alkynes have lower pKa values and are, therefore, more acidic. For example, the pKa values for ethane, ethene, and acetylene are 51, 44, and 25, respectively, as shown here.
9.6K