Video Experimental Relacionado

Updated: Jan 15, 2026

Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones

Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones

Published on: February 7, 2019

Transformaciones de los diastereómeros inducidas por la cristalización de los ciclopropanos donantes y receptores

Aidan J Clarkson¹, Seth O Fremin¹, Jeffrey S Johnson¹

¹Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States.

Journal of the American Chemical Society

|October 15, 2025

Resumen

Los investigadores desarrollaron transformaciones diastereoméricas inducidas por cristalización (CIDT) para los ciclopropanos donante-aceptor (D-A). Este método proporciona bloques de construcción quirales para la síntesis estereoselectiva, lo que permite el aislamiento de diastereómeros específicos a través de la cristalización controlada.

Área de la Ciencia:

Química orgánica
Estereoquímica
Ciencia de la cristalización

Sus antecedentes:

Los componentes quirales no racémicos son cruciales para la síntesis estereospecífica y estereoselectiva.
Los ciclopropanos receptor-donantes (D-A) son productos intermedios sintéticos muy valiosos.
Se necesitan métodos eficientes para acceder a los enantiopuros y a los ciclopropanos diastereoméricamente puros.

Objetivo del estudio:

Informar sobre las primeras transformaciones diastereoméricas inducidas por cristalización (CIDT) de los ciclopropanos D-A.
Desarrollar métodos para acceder a los ciclopropanos quirales no racémicos.
Para permitir el aislamiento estereoselectivo de los diastereómeros de ciclopropano.

Principales métodos:

La epimerización catalizada por el ácido de Lewis de los ciclopropanos D-A sustituidos por anilina a través de la escisión reversible del enlace C-C.
Formación de sales de anilinio para mejorar la cristalinidad y controlar la epimerización.
Cristalización estereoselectiva con capacidad de conmutación dependiente de la temperatura para el aislamiento de los diastereómeros.
La epimerización promovida por el disolvente permite la CIDT espontánea sin ácidos de Lewis.

Principales resultados:

Demostró los primeros CIDT de D-A ciclopropanos, produciendo bloques de construcción quirales no racémicos.
Se obtiene un alto rendimiento y enriquecimiento diastereomérico de diastereómeros de ciclopropano aislados.
Productos aislados por filtración directa, lo que simplifica la purificación.
Se ha demostrado un enfoque CIDT escalable (multidecagrama) impulsado por solventes.

Conclusiones:

Los CIDT ofrecen una nueva vía para los ciclopropanos y derivados diastereoméricamente y enantioméricamente puros.
Las estrategias de epimerización promovidas por ácido de Lewis y solventes proporcionan un acceso versátil a los ciclopropanos quirales.
Los métodos desarrollados facilitan el aislamiento eficiente de los estereoisómeros deseados sin una purificación extensa.

Más Videos Relacionados

Depolymerizable Olefinic Polymers Based on Fused-Ring Cyclooctene Monomers

Depolymerizable Olefinic Polymers Based on Fused-Ring Cyclooctene Monomers

Published on: December 16, 2022

Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene

Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene

Published on: March 20, 2017

Videos de Conceptos Relacionados

[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction

[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction

The Diels–Alder reaction is an example of a thermal pericyclic reaction between a conjugated diene and an alkene or alkyne, commonly referred to as a dienophile. The reaction involves a concerted movement of six π electrons, four from the diene and two from the dienophile, forming an unsaturated six-membered ring. As a result, these reactions are classified as [4+2] cycloadditions.

Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry

Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry

Diels–Alder reactions between cyclic dienes locked in an s-cis configuration and dienophiles yield bridged bicyclic products.

Diels–Alder Reaction Forming Cyclic Products: Stereochemistry

Diels–Alder Reaction Forming Cyclic Products: Stereochemistry

The Diels–Alder reaction is one of the robust methods for synthesizing unsaturated six-membered rings. The reaction involves a concerted cyclic movement of six π electrons: four π electrons from the diene and two π electrons from the dienophile.

Disubstituted Cyclohexanes: cis-trans Isomerism

Disubstituted Cyclohexanes: cis-trans Isomerism

Depending upon the different spatial orientation of the substituents, the disubstituted cycloalkanes exhibit two types of stereoisomers. The cis isomers have the substituents on the same side of the ring, whereas the trans isomers have the substituents on the opposite sides. These stereoisomers exhibit different physical properties and cannot be interconverted without breaking the carbon-carbon bonds.
In cyclohexane, the substituents can occupy different positions generating distinct isomers....

Cycloaddition Reactions: Overview

Cycloaddition Reactions: Overview

Cycloadditions are one of the most valuable and effective synthesis routes to form cyclic compounds. These are concerted pericyclic reactions between two unsaturated compounds resulting in a cyclic product with two new σ bonds formed at the expense of π bonds. The [4 + 2] cycloaddition, known as the Diels–Alder reaction, is the most common. The other example is a [2 + 2] cycloaddition.

Cycloaddition Reactions: MO Requirements for Thermal Activation

Cycloaddition Reactions: MO Requirements for Thermal Activation

Thermal cycloadditions are reactions where the source of activation energy needed to initiate the reaction is provided in the form of heat. A typical example of a thermally-allowed cycloaddition is the Diels–Alder reaction, which is a [4 + 2] cycloaddition. In contrast, a [2 + 2] cycloaddition is thermally forbidden.