Video Experimental Relacionado

Updated: Jul 9, 2025

Synthesis of a Borylated Ibuprofen Derivative Through Suzuki Cross-Coupling and Alkene Boracarboxylation Reactions

Synthesis of a Borylated Ibuprofen Derivative Through Suzuki Cross-Coupling and Alkene Boracarboxylation Reactions

Published on: November 30, 2022

La catálisis de radicales de boro permite reacciones de cicloisomerización de radicales asimétricos

Chang-Ling Wang¹, Jie Wang¹, Ji-Kang Jin²

¹Key Laboratory of Precision and Intelligent Chemistry, CAS Key Laboratory of Urban Pollutant Conversion, Anhui Province Key Laboratory of Biomass Clean Energy, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, China.

Science (New York, N.Y.)

|November 30, 2023

Resumen

Los radicales borilo ligados al carbeno N-heterocíclico quiral (NHC) catalizan la cicloisomerización de los radicales asimétricos. Este método crea eficientemente productos heterocíclicos quirales valiosos a partir de precursores simples.

Área de la Ciencia:

Química orgánica
Catálisis
Química sintética

Sus antecedentes:

La síntesis enantioselectiva es crucial para crear moléculas quirales.
El desarrollo de nuevos catalizadores para reacciones asimétricas sigue siendo un desafío importante en química.

Objetivo del estudio:

Desarrollar nuevos catalizadores quirales para las reacciones de cicloisomerización radical asimétrica.
Para permitir la síntesis eficiente de valiosos compuestos heterocíclicos quirales.

Principales métodos:

Generación de radicales bóricos quirales N-heterocíclicos (NHC) ligados a partir de complejos NHC-borano.
Utilizando estos radicales de boro como catalizadores en las reacciones de cicloisomerización radical.
Investigar el ciclo catalítico a través de estudios mecanicistas.

Principales resultados:

Se empleó con éxito como catalizadores una familia de radicales bóricos quirales ligados a NHC.
El sistema catalítico desarrollado permitió reacciones de cicloisomerización radical asimétricas.
Los estudios mecanicistas aclararon un ciclo catalítico que involucra la adición de radicales de boro, la transferencia de átomos de hidrógeno, la ciclización y la eliminación.
La subunidad quiral NHC fue identificada como el determinante clave de la enantioselectividad.

Conclusiones:

Los radicales borilo ligados al NHC quiral son catalizadores efectivos para la cicloisomerización de radicales asimétricos.
Esta metodología proporciona una ruta poderosa para la síntesis asimétrica de heterociclos quirales.
La amplia disponibilidad de componentes quirales NHC ofrece ventajas para el control estereoquímico.

Más Videos Relacionados

Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones

Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones

Published on: February 7, 2019

Versatile CO2 Transformations into Complex Products: A One-pot Two-step Strategy

Versatile CO2 Transformations into Complex Products: A One-pot Two-step Strategy

Published on: November 9, 2019

Videos de Conceptos Relacionados

Regioselectivity and Stereochemistry of Hydroboration

Regioselectivity and Stereochemistry of Hydroboration

A significant aspect of hydroboration–oxidation is the regio- and stereochemical outcome of the reaction.
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn...

Radical Reactivity: Intramolecular vs Intermolecular

Radical Reactivity: Intramolecular vs Intermolecular

Radical reactions can occur either intermolecularly or intramolecularly. In an intermolecular radical reaction, a nucleophilic radical adds to an electrophilic alkene or vice versa. In such reactions, the radical and generally the alkene, which is also called the radical trap, are two different molecules. Additionally, for such intermolecular reactions to occur, the radical trap must be active, present in an excess concentration, and the radical starting material must have a weak...

Radical Anti-Markovnikov Addition to Alkenes: Overview

Radical Anti-Markovnikov Addition to Alkenes: Overview

The addition of hydrogen bromide to alkenes in the presence of hydroperoxides or peroxides proceeds via an anti-Markovnikov pathway and yields alkyl bromides.

Hydroboration-Oxidation of Alkenes

Hydroboration-Oxidation of Alkenes

In addition to the oxymercuration–demercuration method, which converts the alkenes to alcohols with Markovnikov orientation, a complementary hydroboration-oxidation method yields the anti-Markovnikov product. The hydroboration reaction, discovered in 1959 by H.C. Brown, involves the addition of a B–H bond of borane to an alkene giving an organoborane intermediate. The oxidation of this intermediate with basic hydrogen peroxide forms an alcohol.

Radical Reactivity: Overview

Radical Reactivity: Overview

Radicals, the highly reactive species, gain stability by undergoing three different reactions. The first reaction involves a radical-radical coupling, in which a radical combines with another radical, forming a spin‐paired molecule. The second reaction is between a radical and a spin‐paired molecule, generating a new radical and a new spin‐paired molecule. The third reaction is radical decomposition in a unimolecular reaction, forming a new radical and a spin‐paired...

Radical Substitution: Allylic Bromination

Radical Substitution: Allylic Bromination

In organic synthesis, the formation of products can be altered by changing the reaction conditions. For example, a dibromo addition product is formed when propene is treated with bromine at room temperature. In contrast, propene undergoes allylic substitution in non-polar solvents at high temperatures to give 3-bromopropene. In order to avoid the addition reaction, the bromine concentration must be kept as low as possible throughout the reaction. This can be achieved using N-bromosuccinimide...