Video Experimental Relacionado

Updated: Sep 17, 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

Conjunto modular de alquenos tetrasubstituidos mediados por boro

Liang Wei¹, Mihai V Popescu², Adam Noble¹

¹School of Chemistry, University of Bristol, Bristol, UK.

|July 3, 2025

Resumen

Los investigadores desarrollaron un método mediado por boro para sintetizar alquenos tetrasubstituidos con un control preciso de la geometría del doble enlace. Este enfoque versátil de la química orgánica permite un acceso eficiente a moléculas complejas, incluidos productos farmacéuticos y naturales.

Área de la Ciencia:

Química orgánica
Química sintética

Sus antecedentes:

Los alquenos son fundamentales en la química orgánica.
La síntesis controlada de alquenos tetrasubstituidos sigue siendo un desafío importante.
Los métodos existentes a menudo carecen de un control preciso sobre la geometría del doble enlace.

Objetivo del estudio:

Desarrollar un método para la síntesis estereocontrolada de alquenos tetrasubstituidos.
Para lograr un control completo sobre la geometría del doble enlace.
Para demostrar la versatilidad del método en la síntesis de moléculas complejas.

Principales métodos:

Ensamblaje mediado por boro de alquenos a partir de alquinas.
Adición síncrona de grupo migratorio y electrófilo a través de la alquina.
Oxidación a ésteres borínicos intermedios
Zweifel olefinación de ésteres borínicos con estereoquímica controlada por las bases.

Principales resultados:

Control completo de la geometría del enlace doble en la síntesis de alquenos tetrasubstituidos.
Los ésteres borínicos intermedios pueden aislarse o utilizarse directamente en reacciones posteriores.
Acceso a diversos isómeros posicionales y estereoisómeros de alquenos tetrasubstituidos.
Aplicación exitosa en la síntesis rápida de moléculas de medicamentos y productos naturales.

Conclusiones:

El método mediado por boro proporciona un acceso eficiente y estereocontrolado a los alquenos tetrasubstituidos.
La metodología ofrece una versatilidad significativa para la síntesis orgánica.
Se revelaron nuevos conocimientos mecanicistas sobre la olefinación de Zweifel que involucra iones de boro no clásicos.

Más Videos Relacionados

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

Preparation of a Corannulene-functionalized Hexahelicene by CopperI-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units

Preparation of a Corannulene-functionalized Hexahelicene by CopperI-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units

Published on: September 18, 2016

Videos de Conceptos Relacionados

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.

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.

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 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...

Halogenation of Alkenes

Halogenation of Alkenes

Halogenation is the addition of chlorine or bromine across the double bond in an alkene to yield a vicinal dihalide. The reaction occurs in the presence of inert and non-nucleophilic solvents, such as methylene chloride, chloroform, or carbon tetrachloride.
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.

Radical Anti-Markovnikov Addition to Alkenes: Mechanism

Radical Anti-Markovnikov Addition to Alkenes: Mechanism

The reaction of hydrogen bromide with alkenes in the presence of hydroperoxides or peroxides proceeds via anti-Markovnikov addition. The radical chain reaction comprises initiation, propagation, and termination steps.
The mechanism starts with chain initiation, which involves two steps. In the first chain initiation step, a weak peroxide bond is homolytically cleaved upon mild heating to form two alkoxy radicals. In the second initiation step, a hydrogen atom is abstracted by the alkoxy...