Video Experimental Relacionado
Updated: Feb 26, 2026
06:46
Facile Preparation of 2Z,4E-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate
Published on: June 21, 2017
8.0K
Carboacilación de Alqueno Ni-Catalizado a través de la activación del enlace C-N de Amida
James A Walker1, Kevin L Vickerman1, Jenna N Humke1
1Department of Chemistry, Iowa State University , Ames, Iowa 50011, United States.
Journal of the American Chemical Society
|July 15, 2017
Resumen
Este estudio introduce una nueva reacción catalizada por níquel para la carboacilación de o-alilbenzamidas utilizando ésteres de pinacol de ácido arilborónico. El método sintetiza eficientemente las 2-benzil-2,3-dihidro-1H-inden-1-onas mediante la activación de enlaces amida-C-N.
Área de la Ciencia:
- Química orgánica
- Catálisis
- Metodología sintética
Sus antecedentes:
- La carboacilación de alqueno es una transformación sintética valiosa.
- Los métodos tradicionales a menudo se basan en la activación del enlace C-C, que puede ser un desafío.
- La activación del enlace amida C-N ofrece una vía alternativa.
Objetivo del estudio:
- Desarrollar una nueva carboacilación formal catalizada por Ni de las o-alilbenzamidas.
- Para utilizar ésteres de pinacol de ácido arilborónico como socios de acoplamiento.
- Establecer una nueva vía para sintetizar las 2-benzil-2,3-dihidro-1H-inden-1-onas.
Principales métodos:
- Se utilizó la catálisis de níquel para activar el enlace C-N de amida.
- El mecanismo de reacción implica la adición oxidativa, la inserción de un alqueno en un enlace Ni (II) -ácilo y la eliminación reductora.
- Se utilizaron como sustratos una variedad de o-alilbenzamidas sustituidas y ésteres de pinacol de ácido arilborónico.
Principales resultados:
- La reacción procedió con exo-selectividad, dando como resultado 2-benzil-2,3-dihidro-1H-inden-1-onas.
- Se obtuvieron rendimientos de moderados a altos (46-99%) para los productos objetivo.
- El ámbito de aplicación incluía diversos ésteres de pinacol de ácido arilborónico y o-alilbenzamidas sustituidas.
Conclusiones:
- Las amidas son sustratos efectivos para la carboacilación de alquenos a través de la activación del enlace C-N.
- Este enfoque ofrece una alternativa práctica a las estrategias de activación de bonos C-C.
- El método desarrollado ofrece una nueva herramienta para sintetizar los derivados de la indenona.
Videos de Conceptos Relacionados
02:24Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
9.2K
Introduction
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
9.2K
02:27Preparation of Alkynes: Alkylation Reaction
12.4K
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.
12.4K
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
3.9K
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...
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...
3.9K
01:19Amines to Amides: Acylation of Amines
3.6K
Various carboxylic acid derivatives (such as acid chlorides, esters, and anhydrides) can be used for the acylation of amines to yield amides. The reaction requires two equivalents of amines. The first amine molecule functions as a nucleophile and attacks the carbonyl carbon to produce a tetrahedral intermediate. This is followed by the loss of the leaving group and restoration of the C=O bond.
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary...
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary...
3.6K
02:13Reduction of Alkenes: Catalytic Hydrogenation
14.5K
Alkenes undergo reduction by the addition of molecular hydrogen to give alkanes. Because the process generally occurs in the presence of a transition-metal catalyst, the reaction is called catalytic hydrogenation.
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the...
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the...
14.5K
01:21Acid-Catalyzed α-Halogenation of Aldehydes and Ketones
5.0K
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...
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...
5.0K