Video Experimental Relacionado
Updated: Jul 27, 2026
09:14
Enzymatic Cascade Reactions for the Synthesis of Chiral Amino Alcohols from L-lysine
Published on: February 16, 2018
Síntesis asimétrica y catalítica de aminas alfa-quirales utilizando un nuevo ligando quiral monóxido de bis
Alessandro A Boezio1, Julien Pytkowicz, Alexandre Côté
1Département de Chimie, Université de Montréal, P.O. Box 6128, Station Downtown, Montréal (Québec), Canada H3C 3J7.
Journal of the American Chemical Society
|November 20, 2003
Resumen
Un nuevo ligando, BozPHOS, permite una síntesis eficiente catalizada por cobre de aminas alfa-quirales a partir de N-fosfinoyliminas y reactivos de dialquilzinco. Este método ofrece altos rendimientos y enantioselectividades incluso con dimetilzinco menos reactivo, utilizando una baja carga de catalizador.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- Catalización asimétrica por catálisis asimétrica.
- Química organometálica Química orgánica de los metales.
Sus antecedentes:
- Las aminas quirales son bloques de construcción cruciales en productos farmacéuticos y agroquímicos.
- Los métodos catalíticos eficientes para sintetizar aminas enantioméricamente puras son muy buscados.
- Las adiciones catalizadas por cobre a las iminas representan una ruta prometedora hacia las aminas quirales.
Objetivo del estudio:
- Desarrollar un ligando novedoso y altamente efectivo para reacciones de adición asimétricas catalizadas por cobre.
- Para demostrar la utilidad del nuevo ligando, BozPHOS, en la síntesis de aminas alfa-quirales.
- Para investigar el rendimiento del ligando con sustratos difíciles como el dimetilzinco.
Principales métodos:
- Adición catalizada por cobre de reactivos de dialquilzinco a las N-fosfinoyliminas.
- Utilizó un ligando de monóxido de fosfina recientemente desarrollado, el monóxido de Me-DuPHOS (BozPHOS).
- Selección de las condiciones de reacción para optimizar el rendimiento, la enantioselectividad y la carga del catalizador.
Principales resultados:
- BozPHOS demostró una alta eficacia como ligando en reacciones catalizadas por el cobre.
- Se obtienen altos rendimientos y excelentes enantioselectividades (ee) para las aminas alfa-quirales.
- El proceso fue efectivo incluso con el dimetilzinco menos reactivo.
- La baja carga del catalizador (3 mol %) fue suficiente para una alta formación de productos.
Conclusiones:
- El monóxido de Me-DuPHOS (BozPHOS) es un ligando altamente efectivo para la síntesis asimétrica catalizada por el cobre de aminas alfa-quirales.
- Esta metodología proporciona una ruta robusta y eficiente a valiosos bloques de construcción de aminas quirales.
- El proceso desarrollado ofrece ventajas significativas que incluyen altos rendimientos, amplio alcance de sustrato y excelente enantioselectividad a bajas cargas de catalizador.
Más Videos Relacionados
Videos de Conceptos Relacionados
02:30Chirality at Nitrogen, Phosphorus, and Sulfur
Chirality is most prevalent in carbon-based tetrahedral compounds, but this important facet of molecular symmetry extends to sp3-hybridized nitrogen, phosphorus and sulfur centers, including trivalent molecules with lone pairs. Here, the lone pair behaves as a functional group in addition to the other three substituents to form an analogous tetrahedral center that can be chiral.
A consequence of chirality is the need for enantiomeric resolution. While this is theoretically possible for all...
A consequence of chirality is the need for enantiomeric resolution. While this is theoretically possible for all...
02:05Prochirality
The concept of prochirality leads to the nomenclature of the individual faces of a molecule and plays a crucial role in the enantioselective reaction. It is a concept where two or more achiral molecules react to produce chiral products. A typical process is the reaction of an achiral ketone to generate a chiral alcohol. Here, the achiral reactant reacts with an achiral reducing agent, sodium borohydride, to generate an equimolar mixture of the chiral enantiomers of the product. For example, an...
02:44Oxidation 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.
02:17Reduction 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...
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...
01:22Preparation of 1° Amines: Azide Synthesis
Direct alkylation of ammonia produces polyalkylated amines, along with a quaternary ammonium salt. To exclusively prepare primary amines, the azide synthesis method can be used.
Azide ions act as good nucleophiles and react with unhindered alkyl halides to form alkyl azides. Alkyl azides do not participate in further nucleophilic substitution reactions, thereby eliminating the chances of polyalkylated products. Alkyl azides are reduced by hydride-based reducing agents, like lithium aluminum...
Azide ions act as good nucleophiles and react with unhindered alkyl halides to form alkyl azides. Alkyl azides do not participate in further nucleophilic substitution reactions, thereby eliminating the chances of polyalkylated products. Alkyl azides are reduced by hydride-based reducing agents, like lithium aluminum...
01:28Preparation of 1° Amines: Gabriel Synthesis
Direct alkylation is not a suitable method for synthesizing amines because it produces polyalkylated products. Gabriel synthesis is the most preferred method to exclusively make primary amines. The method uses phthalimide, which contains a protected form of nitrogen that participates in alkylation only once to predominantly give primary amines.
Strong bases like NaOH or KOH deprotonate the phthalimide to form the corresponding anion, which acts as a nucleophile. Further, the anion attacks an...
Strong bases like NaOH or KOH deprotonate the phthalimide to form the corresponding anion, which acts as a nucleophile. Further, the anion attacks an...