Video Experimental Relacionado

Updated: Jun 4, 2026

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

Hidroxilación alilica catalizada por el iridio enantio y regioselectiva

Martin Gärtner¹, Steffen Mader, Kai Seehafer

¹Organisch-Chemisches Institut der Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, D-69120 Heidelberg, Germany.

Journal of the American Chemical Society

|January 29, 2011

Resumen

Este estudio introduce la primera hidroxilación alilica enantioselectiva, produciendo directamente alcoholes alilicos ramificados utilizando catalizadores de iridio estables al aire y nucleófilos de bicarbonato.

Área de la Ciencia:

Química orgánica es la química orgánica.
La catálisis es la catálisis.
Síntesis asimétrica de síntesis.

Sus antecedentes:

Los alcoholes aliales son valiosos intermediarios sintéticos.
La preparación directa de los alcoholes alelicos ramificados sigue siendo un desafío.
La síntesis enantioselectiva es crucial para los productos farmacéuticos.

Objetivo del estudio:

Desarrollar un nuevo método para la hidroxilación alilica enantioselectiva directa.
Para sintetizar alcoholes alelicos ramificados con un alto control estereoquímico.

Principales métodos:

Los catalizadores de un solo componente de iridio (Ir) utilizados.
Empleado bicarbonato como un nucleófilo.
Investigó una variedad de tipos de sustratos.

Principales resultados:

Logró la primera hidroxilación alilica enantioselectiva para la síntesis directa de alcohol alilico ramificado.
Demostró una excelente regioselectividad y enantioselectividad.
Mostró la estabilidad del catalizador en el aire y el agua.

Conclusiones:

El método desarrollado Ir-catalizado ofrece una ruta eficiente a los alcoholes alelicos con ramificación quiral.
Este enfoque simplifica las vías sintéticas y mejora los resultados estereoquímicos.

Más Videos Relacionados

Chemoselective Preparation of 1-Iodoalkynes, 1,2-Diiodoalkenes, and 1,1,2-Triiodoalkenes Based on the Oxidative Iodination of Terminal Alkynes

Chemoselective Preparation of 1-Iodoalkynes, 1,2-Diiodoalkenes, and 1,1,2-Triiodoalkenes Based on the Oxidative Iodination of Terminal Alkynes

Published on: September 12, 2018

Synthesis of Hypervalent Iodonium Alkynyl Triflates for the Application of Generating Cyanocarbenes

Synthesis of Hypervalent Iodonium Alkynyl Triflates for the Application of Generating Cyanocarbenes

Published on: September 8, 2013

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 stereochemistry.

Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide

Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide

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.

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 Acid-Catalyzed Hydration

Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration

The rate of acid-catalyzed hydration of alkenes depends on the alkene's structure, as the presence of alkyl substituents at the double bond can significantly influence the rate.

Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule

Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule

If a set of reactants can yield multiple constitutional isomers, but one of the isomers is obtained as the major product, the reaction is said to be regioselective. In such reactions, bond formation or breaking is favored at one reaction site over others.
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...

Regioselectivity of Electrophilic Additions-Peroxide Effect

Regioselectivity of Electrophilic Additions-Peroxide Effect

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.