Video Experimental Relacionado
Updated: Mar 7, 2026
08:56
Synthesis of a Borylated Ibuprofen Derivative Through Suzuki Cross-Coupling and Alkene Boracarboxylation Reactions
Published on: November 30, 2022
3.5K
Pd{\displaystyle Pd{\displaystyle Pd{\displaystyle Pd{\displaystyle Pd}{\displaystyle Pd{\displaystyle
Jian He1, Qian Shao1, Qingfeng Wu1
1Department of Chemistry, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States.
Journal of the American Chemical Society
|February 18, 2017
Resumen
Los ligandos quirales permiten la primera borilación enantioselectiva de enlaces C ((sp3) -H en amidas. Este avance proporciona acceso a bloques de construcción quirales valiosos para sintetizar derivados complejos de ácido carboxílico.
Área de la Ciencia:
- Química orgánica
- Catálisis
- Síntesis asimétrica
Sus antecedentes:
- La funcionalización del enlace C-H es una estrategia clave en la síntesis orgánica.
- La síntesis enantioselectiva de los derivados de ácido carboxílico quiral sigue siendo un reto.
- La catálisis de paladio ofrece herramientas poderosas para la activación de C-H.
Objetivo del estudio:
- Desarrollar la primera borilación enantioselectiva catalizada por Pd (II) de enlaces C (sp3) -H.
- Para utilizar ligandos quirales de aminometil oxazolina protegidos por acetil para la inducción asimétrica.
- Para demostrar la utilidad de las amidas quirales β-boriladas generadas.
Principales métodos:
- Catalización del paladio
- Uso de ligandos quirales de aminometil oxazolina protegidos por acetil
- Exploración del alcance del sustrato con amidas carbocíclicas (centros α-terciarios y α-cuaternarios)
Principales resultados:
- La borilación enantioselectiva exitosa de los enlaces C ((sp3) -H en las amidas carbocíclicas.
- Alta compatibilidad con los centros de carbono α-terciario y α-cuaternario estéricamente obstaculizados.
- Formación de amidas quirales β-boriladas como intermediarios versátiles.
Conclusiones:
- Este estudio presenta un nuevo método para la borilación asimétrica de C-H.
- La metodología desarrollada proporciona un acceso eficiente a las amidas quirales β-boriladas.
- Estos sintones son valiosos para la preparación de diversos derivados de ácido carboxílico quiral.
![[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F59739.jpg&w=3840&q=50)
Videos de Conceptos Relacionados
02:36Regioselectivity and Stereochemistry of Hydroboration
9.6K
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 stereochemistry.
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 stereochemistry.
9.6K
01:15α-Bromination of Carboxylic Acids: Hell–Volhard–Zelinski Reaction
3.8K
The method to achieve α-brominated carboxylic acids using a mixture of phosphorus tribromide and bromine is known as the Hell–Volhard–Zelinski reaction. The reaction is catalyzed by phosphorus tribromide, which can be used directly or produced in situ from red phosphorus and bromine. The mechanism comprises PBr3 catalyzed conversion of acid to acid bromide and hydrogen bromide. The acid bromide enolizes to its enol form in the presence of HBr. The nucleophilic enol attacks the...
3.8K
02:47Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
21.7K
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.
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.
21.7K
03:08Hydroboration-Oxidation of Alkenes
11.9K
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.
11.9K
02:35Regioselectivity of Electrophilic Additions-Peroxide Effect
11.4K
In the presence of organic peroxides, the addition of hydrogen bromide to an alkene yields the isomer that is not predicted by Markovnikov’s rule. For example, the addition of hydrogen bromide to 2-methylpropene in the presence of peroxides gives 1-bromo-2-methylpropane. This addition reaction proceeds via a free radical mechanism, which reverses the regioselectivity. The free radical reaction mechanism involves three stages: initiation, propagation, and termination.
11.4K
01:25Radical Anti-Markovnikov Addition to Alkenes: Overview
4.3K
The addition of hydrogen bromide to alkenes in the presence of hydroperoxides or peroxides proceeds via an anti-Markovnikov pathway and yields alkyl bromides.
4.3K