相关实验视频

Updated: May 16, 2025

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

末端-铜-催化使得通过初级氨基的α-C-H功能化实现立体异合

Zijiao Liu^1,2, Panpan Li², Haoyang Wang²

¹Shanghai University of Medicine & Health Sciences Affiliated Sixth People's Hospital South Campus, Shanghai, 201499, China.

Angewandte Chemie (International ed. in English)

|May 5, 2025

概括

这项研究引入了一种新型的催化系统,用于直接非对称的初级氨基的α-合,使得具有高选择性的有价值的性氨基构建块的立体分离合成.

科学领域:

有机化学有机化学
不对称的催化剂.
合成方法论合成方法论

背景情况:

α-Chiral初级胺是药品和农业化学品中的关键中间体.
直接非对称的α-C-H非受保护的初级氨基的功能化是非常理想的,但开发不足,特别是在立体分离合成.
现有的方法通常需要保护/激活氨基组.

研究的目的:

开发一种方法,用于直接的enantio-和 diastereodivergentα-allilation的主要α-amino-chromanone.
为了实现α-三级原胺与邻近的立体中心的立体分离合成.
为了阐明不对称的诱导机制.

主要方法:

采用了三元催化系统,包括化物,铜和.
对未受保护的初级α-氨基基-克罗曼进行了直接的α-C-H化.
运用密度函数理论 (DFT) 计算来研究反应机制.

主要成果:

成功合成了一系列α-三级原胺与邻近的立体中心.
实现了高产量和优异的反和异选择性 (>99% ee,>20:1 dr).
通过操纵性催化剂,证明了能够通过操纵性催化剂来访问所有四种立体同位素的能力.

结论:

开发的催化系统使复杂的奇拉胺胺的高效和立体分离合成成为可能.
该方法避免了氨基保护,简化了合成路线.
DFT计算提供了对不对称的诱导模型的见解.

关键词:

双金属催化剂的使用基拉尔氨基氨基.这就是Chromanone.立体分离合成的合成方法三级催化反应的第三次催化.

更多相关视频

Synthesis of a Borylated Ibuprofen Derivative Through Suzuki Cross-Coupling and Alkene Boracarboxylation Reactions

Synthesis of a Borylated Ibuprofen Derivative Through Suzuki Cross-Coupling and Alkene Boracarboxylation Reactions

Published on: November 30, 2022

Efficient Synthesis of All-Carbon Quaternary Centers via the Conjugate Addition of Functionalized Monoorganozinc Bromides

Efficient Synthesis of All-Carbon Quaternary Centers via the Conjugate Addition of Functionalized Monoorganozinc Bromides

Published on: May 26, 2019

相关概念视频

Preparation of 1° Amines: Azide Synthesis

Preparation of 1° Amines: Azide Synthesis

Direct alkylation of ammonia produces polyalkylated amines, along with a quaternary ammonium salt. To exclusively prepare primary amines, the azide synthesis method can be used.
Azide ions act as good nucleophiles and react with unhindered alkyl halides to form alkyl azides. Alkyl azides do not participate in further nucleophilic substitution reactions, thereby eliminating the chances of polyalkylated products. Alkyl azides are reduced by hydride-based reducing agents, like lithium aluminum...

Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation

Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation

Introduction
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.

Reduction of Alkenes: Asymmetric Catalytic Hydrogenation

Reduction of Alkenes: Asymmetric Catalytic Hydrogenation

Catalytic hydrogenation of alkenes is a transition-metal catalyzed reduction of the double bond using molecular hydrogen to give alkanes. The mode of hydrogen addition follows syn stereochemistry.
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...

Preparation of 1° Amines: Hofmann and Curtius Rearrangement Overview

Preparation of 1° Amines: Hofmann and Curtius Rearrangement Overview

In the presence of an aqueous base and a halogen, primary amides can lose the carbonyl (as carbon dioxide) and undergo rearrangement to form primary amines. This reaction, called the Hofmann rearrangement, can produce primary amines (aryl and alkyl) in high yields without contamination by secondary and tertiary amines.

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.

Acid-Catalyzed α-Halogenation of Aldehydes and Ketones

Acid-Catalyzed α-Halogenation of Aldehydes and Ketones

By replacing an α-hydrogen with a halogen, acid-catalyzed α-halogenation of aldehydes or ketones yields a monohalogenated product
In the first step of the mechanism, the acid protonates the carbonyl oxygen resulting in a resonance-stabilized cation, which subsequently loses an α-hydrogen to form an enol tautomer. The C=C bond in an enol is highly nucleophilic because of the electron-donating nature of the –OH group. Consequently, the double bond attacks an electrophilic...