Video Experimental Relacionado

Updated: Jan 5, 2026

Facile Preparation of 2Z,4E-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate

Facile Preparation of 2Z,4E-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate

Published on: June 21, 2017

Mecanismo de alcociclado mediado por Au (III) de un 1,6-Enyne

Ann Christin Reiersølmoen¹, Dániel Csókás², Imre Pápai²

¹Department of Chemistry , Norwegian University of Science and Technology , Høgskoleringen 5 , 7491 Trondheim , Norway.

Journal of the American Chemical Society

|October 17, 2019

Resumen

Este estudio revela que el oro (III) es un catalizador activo para las reacciones de alcosiciclización, un proceso previamente poco explorado. Los conocimientos mecanicistas muestran que la coordinación alquina con el oro (III) es el paso clave para limitar la tasa.

Área de la Ciencia:

Química organometálica
Catálisis
Síntesis orgánica

Sus antecedentes:

La catálisis del oro, en particular el Au (I), está bien establecida para sintetizar moléculas valiosas.
La catálisis mediada por oro sigue siendo en gran medida inexplorada, con un entendimiento mecanicista limitado.

Objetivo del estudio:

Investigar la alcoxiciclación mediada por Au (III) de las 1,6-eninas.
Para elucidar el mecanismo catalítico utilizando un ligando de piridina-oxazolina bidentado.

Principales métodos:

Espectroscopia de resonancia magnética nuclear combinada (RMN)
Cristalografía de rayos X de un solo cristal
Estudios computacionales de la Teoría Funcional de la Densidad (DFT)

Principales resultados:

Se confirmó que el oro (III) es el catalizador activo en la reacción de alcoxiciclado.
La coordinación de Alkyne con el centro Au (III) fue identificada como el paso limitador de la tasa.
El mecanismo implica la descoordinación del nitrógeno piridino tras la unión alquina.

Conclusiones:

Este trabajo proporciona conocimientos mecanicistas cruciales sobre la catálisis de Au (III).
Los hallazgos allanan el camino para el desarrollo de nuevas metodologías sintéticas utilizando complejos Au ((III).

Más Videos Relacionados

Synthesis of Hypervalent Iodonium Alkynyl Triflates for the Application of Generating Cyanocarbenes

Synthesis of Hypervalent Iodonium Alkynyl Triflates for the Application of Generating Cyanocarbenes

Published on: September 8, 2013

Chemoselective Preparation of 1-Iodoalkynes, 1,2-Diiodoalkenes, and 1,1,2-Triiodoalkenes Based on the Oxidative Iodination of Terminal Alkynes

Chemoselective Preparation of 1-Iodoalkynes, 1,2-Diiodoalkenes, and 1,1,2-Triiodoalkenes Based on the Oxidative Iodination of Terminal Alkynes

Published on: September 12, 2018

Videos de Conceptos Relacionados

Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation

Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation

Introduction
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.

Preparation of Alkynes: Alkylation Reaction

Preparation of Alkynes: Alkylation Reaction

Introduction
Alkylation of terminal alkynes with primary alkyl halides in the presence of a strong base like sodium amide is one of the common methods for the synthesis of longer carbon-chain alkynes. For example, treatment of 1-propyne with sodium amide followed by reaction with ethyl bromide yields 2-pentyne.

α-Alkylation of Ketones via Enolate Ions

α-Alkylation of Ketones via Enolate Ions

Ketones with α protons are deprotonated by strong bases like lithium diisopropylamide (LDA) to form enolate ions. The anion is stabilized by resonance, and its hybrid structure exhibits negative charges on the carbonyl oxygen and the α carbon. This ambident nucleophile can attack an electrophile via two possible sites: the carbonyl oxygen, known as O-attack, or the α carbon, known as C-attack. The nucleophilic attack via the carbanionic site is preferred. This is due to the...

Aldehydes and Ketones with Amines: Enamine Formation Mechanism

Aldehydes and Ketones with Amines: Enamine Formation Mechanism

Enamine formation involves the addition of carbonyl compounds to a secondary amine through a series of reactions. The mechanism begins with the generation of carbinolamine, a nucleophilic attack followed by several proton transfer reactions. The hydroxyl group of the carbinolamine is converted into water to make a better leaving group that can push the reaction forward by eliminating a water molecule. In enamine formation, the last step involves the abstraction of a proton from the α carbon to...

Alkynes to Aldehydes and Ketones: Acid-Catalyzed Hydration

Alkynes to Aldehydes and Ketones: Acid-Catalyzed Hydration

Introduction
Analogous to alkenes, alkynes also undergo acid-catalyzed hydration. While the addition of water to an alkene gives an alcohol, hydration of alkynes produces different products such as aldehydes and ketones.

Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation

Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation

Introduction
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.