Hidrogenación catalizada por iridio altamente enantioselectiva de compuestos heteroaromáticos, las quinolinas
Wen-Bo Wang1, Sheng-Mei Lu, Peng-Yu Yang
1Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China.
Journal of the American Chemical Society
|August 28, 2003
Resumen
Se desarrolló un nuevo método para la hidrogenación altamente enantioselectiva de los derivados de la quinolina. Este enfoque sintetiza de manera eficiente las tetrahidroquinolinas ópticamente activas, incluidos los alcaloides naturales, con un alto exceso enantiomérico.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- Catalización asimétrica por catálisis asimétrica.
Sus antecedentes:
- Los derivados de la quinolina son importantes andamios en la química medicinal.
- El desarrollo de métodos de síntesis asimétricos eficientes para las tetrahidroquinolinas quirales es crucial.
Objetivo del estudio:
- Desarrollar un método de hidrogenación altamente enantioselectivo para los derivados de la quinolina.
- Aplicar esta metodología a la síntesis asimétrica de alcaloides de origen natural.
Principales métodos:
- Se utilizó un precursor del catalizador de iridio ([Ir(COD) Cl]2) combinado con un ligando quiral ((R) -MeO-Biphep) y yodo (I2).
- Aplicó el sistema catalítico desarrollado a la hidrogenación de sustratos de quinolina.
Principales resultados:
- Se ha logrado una hidrogenación altamente enantioselectiva de los derivados de la quinolina.
- Sintetizó tetrahidroquinolinas ópticamente activas con hasta un 96% de exceso enantiomérico (ee).
- Aplicó con éxito el método a la síntesis asimétrica de la angustureína, la galipinina y la cuspareína.
Conclusiones:
- El sistema catalizado por iridio desarrollado proporciona una ruta eficiente a las tetrahidroquinolinas enriquecidas enantioméricamente.
- Esta metodología es valiosa para la síntesis de alcaloides quirales complejos.
Más Videos Relacionados
10:17Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
Published on: February 7, 2019
08:25Development of Heterogeneous Enantioselective Catalysts using Chiral Metal-Organic Frameworks (MOFs)
Published on: January 17, 2020
Videos de Conceptos Relacionados
02:50Catalysis
The presence of a catalyst affects the rate of a chemical reaction. A catalyst is a substance that can increase the reaction rate without being consumed during the process. A basic comprehension of a catalysts’ role during chemical reactions can be understood from the concept of reaction mechanisms and energy diagrams.
02:34Enzymes
Inside living organisms, enzymes act as catalysts for many biochemical reactions involved in cellular metabolism. The role of enzymes is to reduce the activation energies of biochemical reactions by forming complexes with its substrates. The lowering of activation energies favor an increase in the rates of biochemical reactions.
Enzyme deficiencies can often translate into life-threatening diseases. For example, a genetic abnormality resulting in the deficiency of the enzyme G6PD...
Enzyme deficiencies can often translate into life-threatening diseases. For example, a genetic abnormality resulting in the deficiency of the enzyme G6PD...
02:17Regioselectivity 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...
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...
02:57Sharpless Epoxidation
The conversion of allylic alcohols into epoxides using the chiral catalyst was discovered by K. Barry Sharpless and is known as Sharpless epoxidation. The use of a chiral catalyst enables the formation of one enantiomer of the product in excess. This chiral catalyst is mainly a chiral complex of titanium tetraisopropoxide and tartrate ester (specific stereoisomer). The stereoisomer used in the chiral catalyst dictates the formation of the enantiomer of the product. In other words, the use of...
01:27Catalysis
Catalysis influences the rate of chemical reactions by providing an alternative reaction pathway with lower activation energy. A catalyst speeds up a reaction, but it is not consumed during the process. The fundamental principle of catalysis is the ability of a catalyst to alter the reaction mechanism, often introducing a more efficient pathway than the uncatalyzed process.In a catalyzed reaction, the catalyst participates directly in the reaction mechanism. It interacts with reactants to form...
01:22Heterogeneous Catalysis
Heterogeneous catalysis involves a catalyst in a different phase from the reactants. It is a process where the catalyst and the reactants are in distinct phases, typically solid and gas or liquid.Most heterogeneous catalysts are metals, metal oxides, or acids. The list includes transition metals like iron (Fe), cobalt (Co), nickel (Ni), palladium (Pd), platinum (Pt), chromium (Cr), manganese (Mn), tungsten (W), silver (Ag), and copper (Cu). These metals possess partially vacant d orbitals that...