Video Experimental Relacionado
Updated: Feb 22, 2026
07:36
Versatile CO2 Transformations into Complex Products: A One-pot Two-step Strategy
Published on: November 9, 2019
8.4K
Hidrocarboxilación directa β-selectiva de estirenos con CO2 habilitada por catálisis fotorredóxica de flujo continuo
Hyowon Seo1, Aofei Liu1, Timothy F Jamison1
1Department of Chemistry, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
Journal of the American Chemical Society
|September 28, 2017
Resumen
Este estudio introduce un nuevo método para la hidrocarboxilación beta selectiva directa de estirenos utilizando dióxido de carbono (CO2) en condiciones suaves. El enfoque de catálisis fotorredóxica funciona de manera eficiente en sistemas de flujo continuo.
Área de la Ciencia:
- Química orgánica
- Catálisis
- Química sustentable
Sus antecedentes:
- Las reacciones de hidrocarboxilación son cruciales para la síntesis de ácidos carboxílicos.
- El desarrollo de métodos selectivos y eficientes utilizando materias primas abundantes como el CO2 es un desafío clave.
- La catálisis por fotorreducción ofrece una poderosa plataforma para nuevas transformaciones orgánicas.
Objetivo del estudio:
- Desarrollar una hidrocarboxilación beta selectiva directa de los estirenos.
- Para utilizar la presión atmosférica de dióxido de carbono (CO2) como fuente de C1.
- Implementar la reacción bajo catálisis fotorredóxica en un sistema de flujo continuo.
Principales métodos:
- Utilizando la catálisis fotorredóxica para la reacción de hidrocarboxilación.
- Utilizando la química de flujo continuo para una mayor eficiencia y escalabilidad.
- Investigando la reacción con varios estirenos funcionalizados.
Principales resultados:
- Se ha logrado una hidrocarboxilación directa beta-selectiva de los estirenos.
- Se ha utilizado con éxito la presión atmosférica de CO2.
- Se ha demostrado un amplio ámbito de aplicación de sustratos, incluidos los estirenos terminales, los estirenos alfa sustituidos y los estirenos beta sustituidos.
Conclusiones:
- El método desarrollado proporciona una vía eficiente para obtener ácidos carboxílicos sustituidos por beta a partir de estirenos y CO2.
- La catálisis fotorredóxica en flujo continuo es una estrategia viable para la formación sostenible de enlaces C-C.
- Esta metodología amplía la utilidad sintética del CO2 en la síntesis orgánica.
Videos de Conceptos Relacionados
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
01:28Reduction of Benzene to Cyclohexane: Catalytic Hydrogenation
6.0K
Unlike the easy catalytic hydrogenation of an alkene double bond, hydrogenation of a benzene double bond under similar reaction conditions does not take place easily. For example, in the reduction of stilbene, the benzene ring remains unaffected while the alkene bond gets reduced. Hydrogenation of an alkene double bond is exothermic and a favorable process. In contrast, to hydrogenate the first unsaturated bond of benzene, an energy input is needed; that is, the process is endothermic. This is...
6.0K
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
02:36Regioselectivity and Stereochemistry of Hydroboration
9.5K
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 stereochemistry.
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 stereochemistry.
9.5K
02:24Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
9.1K
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.
9.1K
03:08Hydroboration-Oxidation of Alkenes
11.7K
In addition to the oxymercuration–demercuration method, which converts the alkenes to alcohols with Markovnikov orientation, a complementary hydroboration-oxidation method yields the anti-Markovnikov product. The hydroboration reaction, discovered in 1959 by H.C. Brown, involves the addition of a B–H bond of borane to an alkene giving an organoborane intermediate. The oxidation of this intermediate with basic hydrogen peroxide forms an alcohol.
11.7K