Video Experimental Relacionado

Updated: May 2, 2026

Facile Preparation of 2Z,4E-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate

Facile Preparation of 2Z,4E-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate

Published on: June 21, 2017

Hidroacilación regioselectiva de 1,3-dienos por catálisis de cobalto

Qing-An Chen¹, Daniel K Kim, Vy M Dong

¹Department of Chemistry, University of California, Irvine , 4403 Natural Sciences 1, Irvine, California 92697, United States.

Journal of the American Chemical Society

|March 5, 2014

Resumen

Los catalizadores de cobalto permiten la hidroacilación de dienos con aldehídos. Esta reacción produce distintos productos de 1,4-adición o 1,2-hidroacilación dependiendo del tipo de aldehído, mostrando una alta selectividad.

Área de la Ciencia:

Química orgánica es la química orgánica.
La catálisis de la catálisis.
Química organometálica Química orgánica de los metales.

Sus antecedentes:

Las reacciones de hidroacilación son cruciales para la formación de enlaces carbono-carbono.
El desarrollo de métodos catalíticos selectivos para la funcionalización de dienes sigue siendo un desafío.

Objetivo del estudio:

Para explorar la hidroacilación catalizada por cobalto de 1,3-dienos utilizando aldehídos no quelantes.
Para investigar la influencia de la estructura del aldehído en la regioselectividad de la reacción.

Principales métodos:

Utilizó un catalizador de cobalto para la reacción de hidroacilación.
Empleó varios aldehídos aromáticos y alifáticos con 1,3-dienes.
Los productos de reacción analizados mediante métodos espectroscópicos.

Principales resultados:

Los aldehídos aromáticos produjeron predominantemente productos de adición de 1,4.
Los aldehídos alifáticos tienen preferentemente productos de 1,2-hidroacilación.
Los estudios cinéticos apoyaron un mecanismo de ciclización oxidativa.

Conclusiones:

La catálisis de cobalto ofrece una ruta selectiva para la hidroacilación de 1,3-dienes.
La reacción se produce a través de un intermediario de cobaltaciclo con alta regioselectividad y estereoselectividad.
La elección del aldehído dicta el resultado regioquímico de la hidroacilación.

Más Videos Relacionados

Versatile CO2 Transformations into Complex Products: A One-pot Two-step Strategy

Versatile CO2 Transformations into Complex Products: A One-pot Two-step Strategy

Published on: November 9, 2019

Retropinacol/Cross-pinacol Coupling Reactions - A Catalytic Access to 1,2-Unsymmetrical Diols

Retropinacol/Cross-pinacol Coupling Reactions - A Catalytic Access to 1,2-Unsymmetrical Diols

Published on: April 4, 2014

Videos de Conceptos Relacionados

Reduction of Alkenes: Asymmetric Catalytic Hydrogenation

Reduction of Alkenes: Asymmetric Catalytic Hydrogenation

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...

Reduction of Alkenes: Catalytic Hydrogenation

Reduction of Alkenes: Catalytic Hydrogenation

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...

Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation

Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation

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.

Regioselectivity and Stereochemistry of Hydroboration

Regioselectivity and Stereochemistry of Hydroboration

A significant aspect of hydroboration–oxidation is the regio- and stereochemical outcome of the reaction.
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn...

Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration

Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration

The rate of acid-catalyzed hydration of alkenes depends on the alkene's structure, as the presence of alkyl substituents at the double bond can significantly influence the rate.

Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule

Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule

If a set of reactants can yield multiple constitutional isomers, but one of the isomers is obtained as the major product, the reaction is said to be regioselective. In such reactions, bond formation or breaking is favored at one reaction site over others.
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...