Video Experimental Relacionado

Updated: Nov 4, 2025

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

Síntesis total de penicibilaenos a través de la desconstrucción del esqueleto activada por C-C y la desaturación

Yibin Xue¹, Guangbin Dong¹

¹Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States.

Journal of the American Chemical Society

|May 26, 2021

Resumen

Este estudio detalla la primera síntesis total de penicibilaenos A y B utilizando una nueva estrategia "C-C/C-H". El enfoque construye eficientemente esqueletos moleculares complejos y estereocentros, avanzando la síntesis de productos naturales.

Área de la Ciencia:

Química orgánica
Síntesis de productos naturales
Catálisis

Sus antecedentes:

Los sesquiterpenos son una clase diversa de productos naturales con estructuras complejas.
Los penicibilaenos A y B representan objetivos sintéticos únicos y desafiantes.
Las rutas sintéticas eficientes son cruciales para acceder y estudiar estos compuestos.

Objetivo del estudio:

Para lograr la primera síntesis total de los penicibilaenos A y B.
Desarrollar y mostrar una nueva estrategia sintética "C-C/C-H".
Explorar métodos catalíticos para la construcción de arquitecturas moleculares complejas.

Principales métodos:

Empleó una transformación de "corte y costura" catalizada por Rh para la formación de enlaces C-C.
Utilizó una estrategia de relevo de desaturación para introducir estereocentros a través de la funcionalización C-H.
Sintetizó las moléculas objetivo en un paso conciso de 13 y 14 (secuencia lineal más larga).

Principales resultados:

Construido con éxito el esqueleto único del dodecano.
Establecido un centro cuaternario de carbono utilizando la etapa "C-C".
Se introdujeron los estereocentros de 1,3,5 tríadas a través de la etapa "CH".

Conclusiones:

El enfoque "C-C/C-H" desarrollado proporciona una ruta eficiente a los penicibilaenos A y B.
Se obtuvieron conocimientos catalíticos y mecanicistas clave para la activación de C-C y la funcionalización de C-H.
Esta síntesis establece un precedente para el acceso a productos naturales complejos.

Más Videos Relacionados

Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions

Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions

Published on: July 17, 2020

Solid-phase Synthesis of [4.4] Spirocyclic Oximes

Solid-phase Synthesis of [4.4] Spirocyclic Oximes

Published on: February 6, 2019

Videos de Conceptos Relacionados

Pericyclic Reactions: Introduction

Pericyclic Reactions: Introduction

Pericyclic reactions are organic reactions that occur via a concerted mechanism without generating any intermediates. The reactions proceed through the movement of electrons in a closed loop to form a cyclic transition state, where rearrangement of the σ and π bonds yields specific products.
Pericyclic reactions can be classified into three categories: electrocyclic reactions, cycloaddition reactions, and sigmatropic rearrangements. Electrocyclic reactions and sigmatropic...

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.

[3,3] Sigmatropic Rearrangement of 1,5-Dienes: Cope Rearrangement

[3,3] Sigmatropic Rearrangement of 1,5-Dienes: Cope Rearrangement

The Cope rearrangement is classified as a [3,3] sigmatropic shift in 1,5-dienes, leading to a more stable, isomeric 1,5-diene. The reaction involves a concerted movement of six electrons, four from two π bonds and two from a σ bond, via an energetically favorable chair-like transition state.

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.

Thermal Electrocyclic Reactions: Stereochemistry

Thermal Electrocyclic Reactions: Stereochemistry

The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.

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.