相关实验视频

Updated: Nov 2, 2025

Synthesis of pH Dependent Pyrazole, Imidazole, and Isoindolone Dipyrrinone Fluorophores using a Claisen-Schmidt Condensation Approach

Synthesis of pH Dependent Pyrazole, Imidazole, and Isoindolone Dipyrrinone Fluorophores using a Claisen-Schmidt Condensation Approach

Published on: June 10, 2021

通过连续的6π电循环/环收缩合成Pyrroles

Franz-Lucas Haut¹, Niklas J Feichtinger¹, Immanuel Plangger¹

¹Institute of Organic Chemistry and Center for Molecular Biosciences, Leopold-Franzens-University Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria.

Journal of the American Chemical Society

|June 9, 2021

概括

这项研究引入了一种使用2,5-二基合成多替代的新方法. 该过程涉及环开放以形成二烯,随后在温和条件下与胺-T三水合物形成.

科学领域:

有机合成
异环化学
合成方法的发展

背景情况:

醇是药品和天然产品中发现的关键异环化合物.
现有的合成途径可以复杂,需要严苛的条件.
开发高效和模块化合成策略对于获取多种醇衍生物至关重要.

研究的目的:

开发一个模块化和高效的合成入口到多替代 pyrroles.
用随时可用的2,5-二基作为起始材料.
建立一个温和和可访问的反应协议,以合成醇.

主要方法:

2,5-二二的环开放产生1,3-二.
通过1,3-二烯与胺-T三水合物的反应形成醇.
反应条件的优化,包括温度,溶剂和前体的修改.
密度功能理论 (DFT) 研究以阐明反应机制.

主要成果:

从2,5-二基中成功合成多替代.
在环境温度下,在不干燥的溶剂中进行转化.
通过精心调整前体电子和硬体来隔离关键中间体.
DFT研究发现了一种涉及6π电循环和环收缩的机制.

结论:

已经建立了一种新的,模块化的,高效的合成途径,以获得多替代.
这种方法提供了一种使用廉价试剂和温和条件的实用方法.
机械学见解为异环化学的进一步合成发展提供了基础.

更多相关视频

Functionalized Spirocyclic Heterocycle Synthesis and Cytotoxicity Assay

Functionalized Spirocyclic Heterocycle Synthesis and Cytotoxicity Assay

Published on: February 9, 2021

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

相关概念视频

Thermal and Photochemical Electrocyclic Reactions: Overview

Thermal and Photochemical Electrocyclic Reactions: Overview

Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.

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.

Preparation and Reactions of Sulfides

Preparation and Reactions of Sulfides

Sulfides are the sulfur analog of ethers, just as thiols are the sulfur analog of alcohol. Like ethers, sulfides also consist of two hydrocarbon groups bonded to the central sulfur atom. Depending upon the type of groups present, sulfides can be symmetrical or asymmetrical. Symmetrical sulfides can be prepared via an SN2 reaction between 2 equivalents of an alkyl halide and one equivalent of sodium sulfide.

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.

Photochemical Electrocyclic Reactions: Stereochemistry

Photochemical Electrocyclic Reactions: Stereochemistry

The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation

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...