Video Experimental Relacionado
Updated: Mar 23, 2026
08:56
Synthesis of a Borylated Ibuprofen Derivative Through Suzuki Cross-Coupling and Alkene Boracarboxylation Reactions
Published on: November 30, 2022
3.5K
Oxidación selectiva de una amina intramolecular activa/borano frustrado por el par de Lewis con oxígeno
Tongdao Wang1, Gerald Kehr1, Lei Liu2
1Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster , Corrensstrasse 40, 48149 Münster, Germany.
Journal of the American Chemical Society
|March 22, 2016
Resumen
Este estudio detalla una nueva reacción entre un par de Lewis frustrado por aminas/borano (FLP) y el oxígeno molecular. La investigación demuestra la oxidación selectiva de los FLPs, dando lugar a una sal única de tetrahidroisoxazolio/borato en condiciones ambientales.
Área de la Ciencia:
- Química organometálica
- Catálisis
- Química supramolecular
Sus antecedentes:
- Los pares de Lewis frustrados (FLP) son típicamente conocidos por reacciones que involucran moléculas pequeñas como H2.
- Las reacciones de oxidación son poco comunes en la química de FLP.
- Los FLP intramoleculares ofrecen perfiles de reactividad únicos.
Objetivo del estudio:
- Investigar la reactividad de un FLP amino/borano con el oxígeno molecular.
- Para explorar las vías de oxidación selectiva en la química de FLP.
- Caracterizar el producto de la reacción FLP-oxígeno.
Principales métodos:
- Síntesis de un FLP amino/borano con puente de trimetileno mediante hidroboración.
- Reacción del FLP con el oxígeno molecular (dióxido) en condiciones ambientales.
- Caracterización de la sal resultante y investigación mecanicista utilizando cálculos DFT.
Principales resultados:
- La FLP amina/borano reacciona selectivamente con el oxígeno molecular.
- Una nueva sal de tetrahidroisoxazolio/borato se forma rápidamente en condiciones ambientales.
- También se ha demostrado que el FLP es un reactivo activo para la división del hidrógeno.
Conclusiones:
- Este trabajo amplía el alcance de reacción conocido de los pares de Lewis frustrados para incluir la oxidación selectiva con oxígeno.
- Los hallazgos proporcionan información sobre el mecanismo de oxidación de FLP y la formación de sales heterocíclicas únicas.
- El sistema FLP desarrollado muestra potencial para aplicaciones catalíticas que implican oxidación o activación de hidrógeno.
Videos de Conceptos Relacionados
02:36Regioselectivity and Stereochemistry of Hydroboration
9.7K
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.
9.7K
03:08Hydroboration-Oxidation of Alkenes
12.1K
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.
12.1K
02:47Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
21.8K
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.
21.8K
02:44Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
13.3K
Alkenes are converted to 1,2-diols or glycols through a process called dihydroxylation. It involves the addition of two hydroxyl groups across the double bond with two different stereochemical approaches, namely anti and syn. Dihydroxylation using osmium tetroxide progresses with syn stereochemistry.
13.3K
02:35Regioselectivity of Electrophilic Additions-Peroxide Effect
11.5K
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.
11.5K
02:15Preparation of Alcohols via Addition Reactions
8.1K
Overview
The acid-catalyzed addition of water to the double bond of alkenes is a large-scale industrial method used to synthesize low-molecular-weight alcohols. An acidic atmosphere is required to allow the hydrogen in the water molecule to act as an electrophile and attack the double bond in an alkene. The addition of a proton to the double bond creates a carbocation intermediate. The proton preferentially bonds to the less substituted end of the double bond to create a more stable carbocation...
The acid-catalyzed addition of water to the double bond of alkenes is a large-scale industrial method used to synthesize low-molecular-weight alcohols. An acidic atmosphere is required to allow the hydrogen in the water molecule to act as an electrophile and attack the double bond in an alkene. The addition of a proton to the double bond creates a carbocation intermediate. The proton preferentially bonds to the less substituted end of the double bond to create a more stable carbocation...
8.1K