Video Experimental Relacionado
Updated: Apr 12, 2026
07:30
A Direct, Regioselective and Atom-Economical Synthesis of 3-Aroyl-N-hydroxy-5-nitroindoles by Cycloaddition of 4-Nitronitrosobenzene with Alkynones
Published on: January 21, 2020
8.8K
Química orgánica. químico orgánico. Práctica hidroaminación de las olefinas con nitroarenos
Jinghan Gui1, Chung-Mao Pan1, Ying Jin1
1Department of Chemistry, Scripps Research Institute, La Jolla, CA 92037, USA.
Science (New York, N.Y.)
|May 23, 2015
Resumen
Este estudio introduce un nuevo método para sintetizar aminas secundarias a partir de olefinas y nitro-heteroarenas. El proceso eficiente y quimioselectivo tolera varios grupos funcionales, ofreciendo una alternativa versátil para la síntesis de aminas.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- Química sintética de la química sintética.
Sus antecedentes:
- La síntesis y la funcionalización de aminas son cruciales en varias aplicaciones químicas.
- Los métodos existentes para la síntesis de arilamina tienen limitaciones en el alcance del sustrato y la tolerancia del grupo funcional.
Objetivo del estudio:
- Desarrollar un método novedoso, eficiente y quimioselectivo para la síntesis de aminas secundarias.
- Para utilizar productos químicos de materias primas fácilmente disponibles como las olefinas y las nitro ((hetero)) arenas.
Principales métodos:
- Un nuevo protocolo sintético que involucra la reacción de las olefinas con los nitro (y hetero) arenas.
- Exploración de una presunta vía mediada por radicales para la formación de aminas.
- Cribado de más de 100 combinaciones de sustrato para evaluar el alcance de la reacción y la tolerancia del grupo funcional.
Principales resultados:
- Síntesis exitosa de aminas secundarias a través de una hidroaminación formal de olefinas.
- Se logra una alta quimioselectividad, lo que permite la síntesis de aminas estéricamente obstaculizadas.
- Tolerancia demostrada a numerosos grupos funcionales no protegidos, incluidos los alcoholes, aminas y ácidos borónicos.
- Ortogonalidad con métodos establecidos como los acoplamientos de Buchwald-Hartwig y Ullmann, tolerando haluros de arilo y compuestos de carbonilo.
Conclusiones:
- El protocolo desarrollado ofrece una ruta simple, operacionalmente sencilla y versátil a las aminas secundarias.
- Este método amplía el conjunto de herramientas para la síntesis de aminas, particularmente para moléculas complejas con grupos funcionales sensibles.
Videos de Conceptos Relacionados
01:29Preparation of Amines: Reduction of Oximes and Nitro Compounds
4.9K
Oximes can be reduced to primary amines using catalytic hydrogenation, hydride reduction, or sodium metal reduction. The reduction of aliphatic and aromatic nitro compounds to primary amines takes place by either catalytic hydrogenation or by using active metals like Fe, Zn, and Sn in the presence of an acid.
Though catalytic hydrogenation can reduce nitrobenzenes, the reduction is nonselective in the presence of other functional groups. For instance, if nitrobenzene contains an aldehyde group,...
Though catalytic hydrogenation can reduce nitrobenzenes, the reduction is nonselective in the presence of other functional groups. For instance, if nitrobenzene contains an aldehyde group,...
4.9K
02:47Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
22.0K
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.
22.0K
03:08Hydroboration-Oxidation of Alkenes
12.5K
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.
12.5K
01:19Preparation of Carboxylic Acids: Hydrolysis of Nitriles
6.7K
Nitriles (R–CN) can be converted into carboxylic acids (R–COOH) upon treatment with aqueous acids, i.e., upon hydrolysis of nitriles. Under base-catalyzed conditions, carboxylate anions (R–COO−) are formed.
6.7K
02:36Regioselectivity and Stereochemistry of Hydroboration
9.8K
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.
9.8K
01:12Preparation of Nitriles
2.8K
One of the common methods to prepare nitriles is the dehydration of amides. This method requires strong dehydrating agents like phosphorous pentoxide or boiling acetic anhydride for converting amides to nitriles. Another reagent namely, thionyl chloride also accomplishes the dehydration of amides, where amide acts as a nucleophile. The first step of the mechanism involves the nucleophilic attack by the amide on the thionyl chloride to form an intermediate. In the next step, the electron pairs...
2.8K