Video Experimental Relacionado
Updated: Jul 6, 2026
06:00
One-pot Microwave-assisted Conversion of Anomeric Nitrate-esters to Trichloroacetimidates
Published on: January 15, 2018
Ataque de aminas en alquenos coordinados: una interconversión de los productos anti-Markovnikoff a los productos
Ruslan Pryadun1, Dinesh Sukumaran, Robert Bogadi
1Department of Chemistry, University at Buffalo, State University of New York, Buffalo, New York 14260, USA.
Journal of the American Chemical Society
|September 30, 2004
Resumen
Los complejos de alquenos de platino reaccionan con la dietilamina. Los alquenos más pequeños sufren un ataque nucleofílico, formando productos anti-Markovnikoff que se convierten en productos de Markovnikoff, mientras que los alquenos más grandes son desplazados por la amina.
Área de la Ciencia:
- Química organometálica Química orgánica de los metales.
- Coordinación Química de la Coordinación
- La catálisis del platino.
Sus antecedentes:
- Los complejos de platino con ligandos de alqueno son importantes en la catálisis.
- Comprender la reactividad de estos complejos con los nucleófilos es crucial para las aplicaciones sintéticas.
Objetivo del estudio:
- Para sintetizar y caracterizar una serie de complejos de alquenos de platino.
- Para investigar la reacción de estos complejos con dietilamina.
- Para aclarar el mecanismo y la regioselectividad de la adición de dietilamina a los alquenos coordinados.
Principales métodos:
- Síntesis de complejos de alquenos de platino PtCl ((2) (((PPh ((3)) (((alqueno) para varios alquenos.
- Caracterización mediante espectroscopia de RMN y cristalografía de rayos X.
- Reacción de complejos con dietilamina para estudiar el ataque nucleófilo y la sustitución.
Principales resultados:
- Se preparó y caracterizó con éxito una serie de complejos de alquenos de platino.
- Los alquenos desplazados por dietilamina en complejos con 1-hexeno, 1-octeno y 1-deceno.
- Se produjo un ataque nucleófilo de la dietilamina sobre alquenos coordinados más pequeños (propeno, 1-buteno), dando inicialmente productos anti-Markovnikoff.
- Los adductos anti-Markovnikoff se isomerizan en productos de Markovnikoff a temperatura ambiente sin la disociación de las aminas.
Conclusiones:
- La reactividad de los complejos de alquenos de platino con dietilamina depende del tamaño del alqueno.
- Se propuso una vía mecanicista que involucra el ataque nucleófilo y la posterior isomerización para alquenos más pequeños.
- Estos hallazgos proporcionan información sobre el comportamiento de los compuestos de organoplatino en las reacciones de adición nucleófila.
Más Videos Relacionados
Videos de Conceptos Relacionados
01:18Nucleophilic Addition to the Carbonyl Group: General Mechanism
The carbonyl carbon in an aldehyde or ketone is the site of a nucleophilic attack due to its electron-deficient nature. Depending on the strength of the incoming nucleophile, the reaction occurs via different mechanistic pathways.
A stronger nucleophile can directly attack the electrophilic center, the carbonyl carbon. The HOMO orbital of the nucleophile interacts with the LUMO (π* antibonding) orbital present on the carbonyl carbon. This interaction breaks the π bond and shifts the π bonding...
A stronger nucleophile can directly attack the electrophilic center, the carbonyl carbon. The HOMO orbital of the nucleophile interacts with the LUMO (π* antibonding) orbital present on the carbonyl carbon. This interaction breaks the π bond and shifts the π bonding...
01:21Acid-Catalyzed α-Halogenation of Aldehydes and Ketones
By replacing an α-hydrogen with a halogen, acid-catalyzed α-halogenation of aldehydes or ketones yields a monohalogenated product
In the first step of the mechanism, the acid protonates the carbonyl oxygen resulting in a resonance-stabilized cation, which subsequently loses an α-hydrogen to form an enol tautomer. The C=C bond in an enol is highly nucleophilic because of the electron-donating nature of the –OH group. Consequently, the double bond attacks an electrophilic halogen to form a...
In the first step of the mechanism, the acid protonates the carbonyl oxygen resulting in a resonance-stabilized cation, which subsequently loses an α-hydrogen to form an enol tautomer. The C=C bond in an enol is highly nucleophilic because of the electron-donating nature of the –OH group. Consequently, the double bond attacks an electrophilic halogen to form a...
00:51Base-Promoted α-Halogenation of Aldehydes and Ketones
α-Halogenation of aldehydes and ketones is a reaction involving the substitution of α hydrogens with halogens in the presence of a base. The reaction begins with the abstraction of α hydrogen by the base to produce a nucleophilic enolate ion. This intermediate undergoes a subsequent nucleophilic substitution with the halogen to produce a monohalogenated carbonyl compound. If the starting substrate has more than one α hydrogen, it is difficult to stop the reaction at the stage of...
01:16Amines to Alkenes: Hofmann Elimination
Alkenes can be obtained from amines via an E2 elimination. The amine is first converted into a good leaving group, such as a quaternary ammonium salt. This is accomplished by treating the amine with an excess of alkyl halide, which results in a halide salt. Next, the halide salt is transformed into a hydroxide salt that functions as a base to enable elimination.
Under thermal conditions, the hydroxide can abstract a proton from the β carbon; this generates an alkene with the simultaneous...
Under thermal conditions, the hydroxide can abstract a proton from the β carbon; this generates an alkene with the simultaneous...
01:14Amines to Alkenes: Cope Elimination
Cope elimination reaction involves the conversion of tertiary amines to alkene using hydrogen peroxide under thermal conditions, as depicted in figure 1.
01:17Reactions of α-Halocarbonyl Compounds: Nucleophilic Substitution
Nucleophilic substitution in α-halocarbonyl compounds can be achieved via an SN2 pathway. The reaction in α-haloketones is generally carried out with less basic nucleophiles. The use of strong basic nucleophiles leads to the generation of α-haloenolate ions, which often participate in other side reactions.