Video Experimental Relacionado
Updated: Jun 22, 2026
10:51
The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes
Published on: April 10, 2015
Los complejos de nitruro de molibdeno con ligandos Ph3SiO son precatalizadores extremadamente prácticos y tolerantes
Martin Bindl1, Robert Stade, Eike K Heilmann
1Max-Planck-Institut fur Kohlenforschung, D-45470 Mulheim/Ruhr, Germany.
Journal of the American Chemical Society
|June 19, 2009
Resumen
Nuevos complejos de nitruro de molibdeno demuestran una excelente actividad catalítica en la metátesis de alquinos. Un complejo, el adducto 11, es estable al aire y tolerante a grupos funcionales ampliamente, simplificando su uso en la síntesis de moléculas complejas.
Área de la Ciencia:
- Química organometálica Química orgánica de los metales.
- La catálisis de la catálisis.
Sus antecedentes:
- La metátesis de alquinos es una reacción crucial en la síntesis orgánica.
- Los precatalizadores de metástasis de alquinos existentes a menudo carecen de estabilidad o facilidad de manejo.
Objetivo del estudio:
- Desarrollar nuevos, estables y altamente activos precatalizadores basados en nitruro de molibdeno para la metátesis de alquinos.
- Evaluar el rendimiento catalítico y la tolerancia del grupo funcional de estos nuevos sistemas.
Principales métodos:
- Preparación in situ del complejo de nitruro de molibdeno [(Ph(3) SiO) ((3) Mo[triple enlace]N] (10) a partir de [(Me(3) SiO) ((2) (((Me(3) Si) ((2) N) Mo[triple enlace]N] (9) y Ph(3) SiOH.
- Formación y aislamiento del adducto de piridina [pyridine) Ph) SiO) Mo [triple enlace] N] (11).
- Prueba de la actividad catalítica de los complejos 10 y 11 en varias reacciones de metátesis alquina.
Principales resultados:
- El complejo 10 y su adducto de piridina 11 exhiben una excelente actividad catalítica en diversas reacciones de metátesis de alquinos.
- Adduct 11 es estable en el aire y fácil de manejar, superando a los precatalizadores existentes en usabilidad.
- El sistema catalítico demuestra una amplia compatibilidad de grupos funcionales, incluyendo ésteres, amidas y alcoholes protegidos.
- Síntesis exitosa de intermediarios clave para productos naturales bioactivos como la epothilona A y el análogo de latrunculina.
Conclusiones:
- Los nuevos complejos de nitruro de molibdeno, particularmente el adducto 11 estable al aire, representan un avance significativo en la catálisis de la metástasis de alquino.
- Estos precatalizadores ofrecen una mayor estabilidad, facilidad de uso y un amplio alcance de sustrato, facilitando la síntesis de moléculas orgánicas complejas.
- La compatibilidad del sistema con varios grupos funcionales lo convierte en una herramienta versátil para los químicos sintéticos.
Más Videos Relacionados
09:37Imine Metathesis by Silica-Supported Catalysts Using the Methodology of Surface Organometallic Chemistry
Published on: October 18, 2019
19:58Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions
Published on: July 30, 2017
Videos de Conceptos Relacionados
02:51Metal-Ligand Bonds
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
01:12Preparation of Nitriles
One of the common methods to prepare nitriles is the dehydration of amides. This method requires strong dehydrating agents like phosphorous pentoxide or boiling acetic anhydride for converting amides to nitriles. Another reagent namely, thionyl chloride also accomplishes the dehydration of amides, where amide acts as a nucleophile. The first step of the mechanism involves the nucleophilic attack by the amide on the thionyl chloride to form an intermediate. In the next step, the electron pairs...
00:55Nitriles to Amines: LiAlH4 Reduction
Nitriles are reduced to amines in the presence of strong reducing agents like lithium aluminum hydride through a typical nucleophilic acyl substitution. The reaction requires two equivalents of the reducing agent. The reducing agent acts as a source of hydride ions.
As shown below, the mechanism involves three steps. Firstly, the hydride ion acting as a nucleophile attacks the nitrile carbon to form an anion. In the second step, a second equivalent of the hydride ion attacks the anion to...
As shown below, the mechanism involves three steps. Firstly, the hydride ion acting as a nucleophile attacks the nitrile carbon to form an anion. In the second step, a second equivalent of the hydride ion attacks the anion to...
00:57Nitriles to Ketones: Grignard Reaction
Organomagnesium halides, commonly known as Grignard reagents, convert nitriles to ketones and proceed through a nucleophilic acyl substitution. Nitriles react with a Grignard reagent, followed by an aqueous acid, to yield ketones. The reaction introduces a new carbon–carbon bond. The alkyl–magnesium bond in the Grignard reagent is highly polar, so the alkyl carbon develops a carbanionic character and acts as a nucleophile.
The mechanism begins with a nucleophilic attack by the Grignard reagent...
The mechanism begins with a nucleophilic attack by the Grignard reagent...
01:23Properties of Organometallic Compounds
Organometallic compounds are compounds that contain a carbon–metal bond. Carbon belongs to an organyl group like alkyl, aryl, allyl, or benzyl groups. The metal can be from Group I or Group II of the periodic table, a transition metal, or a semimetal.
01:19Complexation Equilibria: The Chelate Effect
In complexation reactions, metal atoms or cations interact with ligands to form donor-acceptor adducts called metal complexes. Ligands that bind through one donor site are monodentate, ligands with two donor sites are bidentate, and those with more than two donor sites are polydentate ligands. For example, ethylene diamine is a bidentate ligand that binds through two nitrogen donor atoms, forming a five-membered ring. EDTA is a polydentate ligand that binds through four oxygen and two nitrogen...