Video Experimental Relacionado

Updated: May 2, 2026

Direct Detection of the Acetate-forming Activity of the Enzyme Acetate Kinase

Direct Detection of the Acetate-forming Activity of the Enzyme Acetate Kinase

Published on: December 19, 2011

La silición intramolecular de enlaces C-H de metilo por catalización enantioselectiva

Bo Su¹, John F Hartwig¹

¹Department of Chemistry, University of California , Berkeley, California 94720, United States.

Journal of the American Chemical Society

|August 19, 2017

Resumen

Este estudio introduce un nuevo método catalizado por iridio para la sililación enantioselectiva de enlaces primarios C ((sp3) -H. La reacción produce eficientemente dihidrobenzosiloles enriquecidos con enantio, lo que permite una mayor funcionalización.

Área de la Ciencia:

Química orgánica
Química organometálica
Catálisis

Sus antecedentes:

La funcionalización del enlace C-H es un área clave en la química sintética.
El desarrollo de métodos enantioselectivos para enlaces C-H no activados sigue siendo un desafío.
La silición intramolecular ofrece una ruta a los heterociclos valiosos que contienen silicio.

Objetivo del estudio:

Desarrollar una silición intramolecular altamente enantioselectiva de enlaces primarios C ((sp3) -H no activados.
Para sintetizar dihidrobenzosiloles enriquecidos con enantio.
Para explorar la utilidad sintética de los enlaces C-Si formados.

Principales métodos:

Utilizando un complejo de iridio ([Ir(COD) OMe]2) con ligandos quirales de nitrógeno.
Utilizando la silición intramolecular de los grupos metilo enantiotópicos.
Funcionalización catalítica de enlaces primarios C ((sp3) -H no activados bajo condiciones suaves.

Principales resultados:

Se han logrado siliciones intramoleculares altamente enantioselectivas de enlaces primarios C ((sp3) -H.
Dihidrobenzosiloles sintetizados en altos rendimientos y enantioselectividades excelentes.
Se ha demostrado la transformación de enlaces C-Si en enlaces C-Cl, C-Br, C-I y C-O.
Se muestran las funcionalizaciones secuenciales C ((sp3) -H y C ((sp2) -H y las silaciones diastereoselectivas.

Conclusiones:

La reacción catalizada por iridio desarrollada proporciona una ruta eficiente a los dihidrobenzosilos enantioenriquecidos.
El método permite la funcionalización versátil de enlaces C-Si y moléculas complejas.
En los estudios mecanicistas preliminares, la escisión C-H se identifica como el paso que determina la velocidad.

Más Videos Relacionados

Targeting Cysteine Thiols for in Vitro Site-specific Glycosylation of Recombinant Proteins

Targeting Cysteine Thiols for in Vitro Site-specific Glycosylation of Recombinant Proteins

Published on: October 4, 2017

In Vitro Directed Evolution of a Restriction Endonuclease with More Stringent Specificity

In Vitro Directed Evolution of a Restriction Endonuclease with More Stringent Specificity

Published on: March 25, 2020

Videos de Conceptos Relacionados

E1 Reaction: Stereochemistry and Regiochemistry

E1 Reaction: Stereochemistry and Regiochemistry

One of the critical aspects of the E1 reaction mechanism, as also observed in E2, is the regiochemistry, with multiple regioisomers obtained as products. In the example discussed, the presence of water as a weak base favors elimination over substitution to generate two alkenes. Given that alkenes’ stability increases with the number of alkyl groups across the double bond, typically, E1 reactions lead to the Zaitsev product, for this is more substituted and stable than the Hofmann product.

Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration

Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration

The rate of acid-catalyzed hydration of alkenes depends on the alkene's structure, as the presence of alkyl substituents at the double bond can significantly influence the rate.

Esters to Carboxylic Acids: Acid-Catalyzed Hydrolysis

Esters to Carboxylic Acids: Acid-Catalyzed Hydrolysis

Hydrolysis of esters under acidic conditions proceeds through a nucleophilic acyl substitution. In the presence of excess water, the reaction proceeds in a reversible manner, forming carboxylic acids and alcohols.
During hydrolysis, the ester is first activated towards nucleophilic attack through the protonation of the carboxyl oxygen atom by the acid catalyst. The protonation makes the ester carbonyl carbon more electrophilic. In the next step, water acts as a nucleophile and adds to the...

Acid-Catalyzed Aldol Addition Reaction

Acid-Catalyzed Aldol Addition Reaction

The aldol reaction of a ketone under acidic conditions successfully forms an unsaturated carbonyl as the final product instead of an aldol. The acid-catalyzed aldol reaction is depicted in Figure 1.

Reactions of Carboxylic Acids: Introduction

Reactions of Carboxylic Acids: Introduction

Carboxylic acids possess an acidic –COOH functional group. The acidity can be attributed to the resonance stabilization of their conjugate base, wherein the negative charge is delocalized over both oxygen atoms.

Amino Acid Catabolism

Amino Acid Catabolism

Microorganisms rely on proteins as an essential carbon and energy source, particularly in environments with limited polysaccharides or lipids. However, proteins are too large to cross the plasma membrane unaided, necessitating enzymatic degradation. Microbes secrete extracellular proteases and peptidases that hydrolyze proteins into peptides, which can then be transported across the membrane. Once inside the cell, intracellular proteases degrade these peptides into free amino acids, which...