Video Experimental Relacionado

Updated: Dec 28, 2025

Catalytic Reactions at Amine-Stabilized and Ligand-Free Platinum Nanoparticles Supported on Titania During Hydrogenation of Alkenes and Aldehydes

Catalytic Reactions at Amine-Stabilized and Ligand-Free Platinum Nanoparticles Supported on Titania During Hydrogenation of Alkenes and Aldehydes

Published on: June 24, 2022

Deshidrogenación sin receptor catalítico de los alcoholes alifáticos

Hiromu Fuse¹, Harunobu Mitsunuma¹, Motomu Kanai¹

¹Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan.

Journal of the American Chemical Society

|February 15, 2020

Resumen

Los investigadores crearon un nuevo sistema catalítico para la deshidrogenación sin aceptor de alcoholes a cetonas utilizando luz visible. Este método eficiente funciona a temperatura ambiente y muestra un amplio alcance de sustrato, incluidas las moléculas complejas.

Área de la Ciencia:

Química orgánica
Catálisis
La fotoquímica

Sus antecedentes:

La deshidrogenación sin receptores es crucial para la síntesis de cetonas a partir de alcoholes.
Los métodos existentes a menudo requieren condiciones duras u oxidantes estequiométricos.

Objetivo del estudio:

Desarrollar un método novedoso, suave y eficiente para la deshidrogenación sin aceptor de alcoholes a cetonas.
Explorar la aplicación de un sistema de catalizador híbrido ternario bajo irradiación de luz visible.

Principales métodos:

Desarrollo de un sistema de catalizador híbrido ternario (catalizador fotorredóxido, catalizador organofosfato, catalizador de níquel).
Utilizando irradiación de luz visible a temperatura ambiente para la reacción.
Investigación del mecanismo de reacción que involucra la transferencia de átomos de hidrógeno, la intercepción de radicales y la eliminación de beta-hidruro.

Principales resultados:

Logró la primera deshidrogenación de alcoholes secundarios alifáticos a cetonas impulsada por luz visible y sin aceptor a temperatura ambiente.
Se ha demostrado un alto rendimiento y selectividad con una amplia gama de sustratos alcohólicos, incluidos los esterilizados.
Se ha aplicado con éxito el sistema catalizador a la esterificación deshidrogenativa cruzada sin aceptor.

Conclusiones:

El sistema de catalizador híbrido ternario desarrollado ofrece un enfoque sostenible y eficiente para la oxidación del alcohol.
La metodología proporciona una alternativa suave para la síntesis y esterificación de cetonas.
Este trabajo amplía el alcance de la catálisis fotorredóxica en la síntesis orgánica.

Más Videos Relacionados

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

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: 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.

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...

Alcohols from Carbonyl Compounds: Reduction

Alcohols from Carbonyl Compounds: Reduction

Reduction is a simple strategy to convert a carbonyl group to a hydroxyl group. The three major pathways to reduce carbonyls to alcohols are catalytic hydrogenation, hydride reduction, and borane reduction.
Catalytic hydrogenation is similar to the reduction of an alkene or alkyne by adding H2 across the pi bond in the presence of transition metal catalysts like Raney Ni, Pd–C, Pt, or Ru. Aldehydes and ketones can be reduced by this method, often under mild to moderate heat (25–100°C) and...

Aldehydes and Ketones with Alcohols: Hemiacetal Formation

Aldehydes and Ketones with Alcohols: Hemiacetal Formation

Similar to water, alcohols can add to the carbonyl carbon of the aldehydes and ketones. The addition of one molecule of alcohol to the carbonyl compound forms the hemiacetal or half acetal. As depicted below, in a hemiacetal, the carbon is directly linked to an OH and OR group.

Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide

Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide

Alkenes are converted to 1,2-diols or glycols through a process called dihydroxylation. It involves the addition of two hydroxyl groups across the double bond with two different stereochemical approaches, namely anti and syn. Dihydroxylation using osmium tetroxide progresses with syn stereochemistry.