Video Experimental Relacionado

Updated: Jan 25, 2026

Efficient Synthesis of All-Carbon Quaternary Centers via the Conjugate Addition of Functionalized Monoorganozinc Bromides

Efficient Synthesis of All-Carbon Quaternary Centers via the Conjugate Addition of Functionalized Monoorganozinc Bromides

Published on: May 26, 2019

Hidroalquilación de las olefinas para formar carbonos cuaternarios

Samantha A Green¹, Tucker R Huffman¹, Ruairí O McCourt¹

¹Department of Chemistry , The Scripps Research Institute , 10550 North Torrey Pines Road , La Jolla , California 92037 , United States.

Journal of the American Chemical Society

|April 30, 2019

Resumen

Los investigadores desarrollaron un nuevo método catalítico para la hidroalquilación, creando estructuras de carbono ramificadas a partir de alquenos y haluros de alquilo simples. Este avance expande la utilidad de las reacciones de transferencia de átomos de hidrógeno de hidrógeno para sintetizar moléculas orgánicas complejas.

Área de la Ciencia:

Química orgánica
Catálisis
Metodología sintética

Sus antecedentes:

La transferencia de átomos de hidrógeno de hidrógeno metálico (MHAT) es un método conocido para funcionalizar alquenos con selectividad de Markovnikov.
Las reacciones MHAT anteriores se limitaron a trampas de radicales π, excluyendo electrófilos sp3.
Se necesitaban nuevos métodos para formar enlaces C-C utilizando sustratos no activados.

Objetivo del estudio:

Desarrollar un nuevo sistema catalítico para la hidroalquilación de olefinas no activadas.
Ampliar el alcance de las reacciones de transferencia de átomos de hidrógeno metal-hidruro para incluir electrófilos sp3.
Para permitir la síntesis de carbono cuaternario alifático.

Principales métodos:

Se utilizó un sistema catalítico dual de manganeso (Mn) y níquel (Ni).
Utilizan haluros de alquilo no activados como socios de acoplamiento electrófilo.
Investigó la reacción con las olefinas no activadas.

Principales resultados:

Se ha conseguido con éxito la hidroalquilación de olefinas no activadas con haluros de alquilo no activados.
Demostró la formación de valiosos centros de carbono cuaternario alifático.
Estableció una nueva vía para la formación de enlaces C(sp3) -C(sp3).

Conclusiones:

El sistema catalítico dual Mn/Ni supera efectivamente las limitaciones anteriores en las reacciones MHAT.
Esta metodología proporciona una nueva herramienta poderosa para sintetizar moléculas orgánicas complejas con centros de carbono cuaternarios.
Los hallazgos abren nuevas vías para la funcionalización de alquenos y la construcción de enlaces C-C.

Más Videos Relacionados

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

Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions

Palladium 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

Carbon Skeletons

Carbon Skeletons

Life on Earth is carbon-based, as all macromolecules that make up living organisms contain carbon atoms. All organic compounds have a carbon backbone. Each carbon atom is tetravalent and can bond with four other atoms, making it an extraordinarily flexible component of biological molecules. Because carbon’s valence electrons are stable, it rarely becomes an ion. As the carbon chain increases in length, structural modifications such as ring structures, double bonds, and branching side...

The Carbon Cycle

The Carbon Cycle

Carbon is the basis of all organic matter on Earth, and is recycled through the ecosystem in two primary processes: one in which carbon is exchanged among living organisms, and one in which carbon is cycled over long periods of time through fossilized organic remains, weathering of rocks, and volcanic activity. Human activities, including increased agricultural practices and the burning of fossil fuels, has greatly affected the balance of the natural carbon cycle.

Olefin Metathesis Polymerization: Overview

Olefin Metathesis Polymerization: Overview

Recently, the development of olefin metathesis polymerization advanced the field of polymer synthesis. Simply put, the reorganization of substituents on their double bonds between two olefins in the presence of a catalyst is known as the olefin metathesis reaction. The use of metathesis reaction for polymer synthesis is called olefin metathesis polymerization.
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists of a...

Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)

Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)

Acyclic diene metathesis polymerization or ADMET polymerization involves cross-metathesis of terminal dienes, such as 1,8-nonadiene, to give linear unsaturated polymer and ethylene. As ADMET is a reversible process, the formed ethylene gas must be removed from the reaction mixture to complete the polymerization process.
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...

Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)

Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)

Ring-opening metathesis polymerization or ROMP involves strained cycloalkenes as starting materials. The mechanism of ROMP proceeds by reacting cycloalkene with Grubbs catalyst to give metallacyclobutane intermediate which undergoes a ring-opening reaction to form new carbene. The new carbene reacts with another molecule of cycloalkene. Repetition of these steps leads to the formation of an unsaturated open-chain polymer product. All these steps are reversible, however, relieving the ring...

Carbonation Shrinkage

Carbonation Shrinkage

Atmospheric CO2 penetrates the concrete's pores and, in the presence of moisture, forms carbonic acid, which then reacts with calcium hydroxide in the hydrated cement, forming calcium carbonate. This process reduces the concrete's volume and is termed carbonation shrinkage.
The concrete's permeability is slightly reduced as calcium carbonate produced during the reaction fills its pores. Furthermore, its strength is slightly enhanced as the water released during the reaction...