Video Experimental Relacionado
Updated: Jul 10, 2026
12:31
Chemoselective Modification of Viral Surfaces via Bioorthogonal Click Chemistry
Published on: August 19, 2012
Desimetrización de la hidroformilación con la ayuda de un grupo planar quiral de dirección del catalizador
Bernhard Breit1, Daniel Breuninger
1Institut für Organische Chemie und Biochemie, Albert-Ludwigs-Universität Freiburg, Germany. bernhard.breit@organik.chemie.uni-freiburg.de
Journal of the American Chemical Society
|August 19, 2004
Resumen
La hidroformilación quiral de bisalkenil- y bisallilcarbinolos se logró utilizando un grupo de dirección de catalizador unido al sustrato. Este método produce aldehídos quirales bifuncionalizados enantioméricamente puros con alta selectividad.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- Catalización asimétrica por catálisis asimétrica.
Sus antecedentes:
- La hidroformilación es una reacción clave para la formación de enlaces carbono-carbono.
- Lograr una alta enantioselectividad en la hidroformilación de sustratos complejos sigue siendo un desafío.
Objetivo del estudio:
- Desarrollar un método para la hidroformilación desimetrizante de los bisalquenil- y bisallilcarbinolos.
- Para lograr altos niveles de estereocontrol en la síntesis de aldehídos quirales.
Principales métodos:
- Empleando un grupo de dirección de catalizador ligado al sustrato quiral, el orto-difenilfosfinoferroceno (o-DPPF).
- Utilizando bisalkenil- y bisallilcarbinolos como sustratos.
Principales resultados:
- Se logró una excelente discriminación de la cara de alqueno diastereotópico y del grupo de alqueno diastereotópico.
- Se obtuvieron aldehídos quirales bifuncionalizados enantioméricamente puros.
Conclusiones:
- El método desarrollado permite una eficiente desimetrización de la hidroformilación.
- Este enfoque proporciona acceso a valiosos bloques de construcción de aldehído quiral.
Videos de Conceptos Relacionados
02:48Conversion of Alcohols to Alkyl Halides
This lesson delves into the conversion of alcohols to corresponding alkyl halides and the mechanism of action for different reagents. Typically, the hydroxyl group is first protonated to convert it to a stable leaving group. Consequently, based on the starting alcohol, the mechanism undergoes either of the nucleophilic substitution routes, SN1 or SN2. Tertiary alkyl halides are made using the two-step SN1 mechanism that occurs via a carbocation intermediate, which is stabilized by...
01:10Radical Chain-Growth Polymerization: Overview
Chain-growth or addition polymerization is successive addition reactions of monomers with a polymer chain. In radical chain-growth polymerization, the reaction proceeds via a free-radical intermediate. The free radical is formed from radical initiators, which spontaneously generate free radicals by homolytic fission. Organic peroxides (such as dibenzoyl peroxide, as shown in Figure 1) or azo compounds are popular radical initiators. A low concentration ratio of radical initiator to monomer is...
01:09Radical Chain-Growth Polymerization: Mechanism
The radical chain-growth polymerization mechanism consists of three steps: initiation, propagation, and termination of polymerization. The polymerization initiates when a free radical generated from the radical initiator adds to the unsaturated bond in the monomer. The unpaired electron of the free radical and one π electron in the unsaturated bond creates a σ bond between the free radical and the monomer. As a result, the other π electron in the unsaturated bond converts this species into the...
01:20Anionic Chain-Growth Polymerization: Overview
The polymerization process that involves carbanion as an intermediate is called anionic polymerization. It is also a type of addition or chain-growth polymerization. Anionic polymerization gets initiated by a strong nucleophile such as an organolithium or a Grignard reagent. The most commonly used initiator for anionic polymerization is butyl lithium. Monomers involved in anionic polymerization must possess a vinyl group bonded to one or two electron-withdrawing groups. For instance,...
01:04Anionic Chain-Growth Polymerization: Mechanism
The mechanism for anionic chain-growth polymerization involves initiation, propagation, and termination steps. In the initiation step, a nucleophilic anion, such as butyl lithium, initiates the polymerization process by attacking the π bond of the vinylic monomer. As a result, a carbanion, stabilized by the electron‐withdrawing group, is generated. The resulting carbanion acts as a Michael donor in the propagation step and attacks the second vinylic monomer, which acts as a Michael acceptor.
00:57Cationic Chain-Growth Polymerization: Mechanism
The cationic polymerization mechanism consists of three steps: initiation, propagation, and termination. In the initiation step of the polymerization process, the π bond of a monomer gets protonated by the Lewis acid catalyst, which is formed from boron trifluoride and water. The protonation of the π bond generates a carbocation stabilized by the electron‐donating group. In the propagation step, the π bond of the second monomer acts as a nucleophile and attacks the generated carbocation,...