関連する実験動画

Updated: Jun 4, 2025

Retropinacol/Cross-pinacol Coupling Reactions - A Catalytic Access to 1,2-Unsymmetrical Diols

Retropinacol/Cross-pinacol Coupling Reactions - A Catalytic Access to 1,2-Unsymmetrical Diols

Published on: April 4, 2014

アルケンの1,1-サイクロアニュレーション反応

Jin-Ping Wang^1,2, Tao Liu¹, Yichen Wu¹

¹State Key Laboratory of Organometallic Chemistry and Shanghai-Hong Kong Joint Laboratory in Chemical Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, CAS 345 Lingling Road, Shanghai 200032, P. R. China.

Journal of the American Chemical Society

|December 18, 2024

まとめ

単純なアルケンから多様な窒素と酸素のヘテロサイクルの効率的な合成を可能にする新しいパラジウム触媒反応. この方法は,幅広い機能群の許容性とリングサイズに対する制御を提供し,複雑な分子製剤を簡素化します.

科学分野:

有機化学
カタリシス
ヘテロサイクル化学

背景:

ヘテロサイクルは医薬品や材料における重要な構造モチーフです.
ヘテロサイクルの製造のための効率的で汎用的な合成方法は非常に求められています.
パラジウム触媒反応は,C-CとC-ヘテロ原子結合形成のための強力なツールを提供します.

研究の目的:

パラジウム触媒による新型 1,1-サイクロアニュレーション反応 (MCAR) の開発.
五つから七つあるアザとオックスヘテロサイクルを合成する.
新しい反応の範囲と限界を様々な基質で探求する.

主な方法:

移動性1,1-サイクロアニュレーション反応のためのパラジウム触媒を用いた.
すぐ手に入るアルケニルアミンとアルケニルアルコールを,原料として使用した.
4-イオドフェノールまたは2-イオドフェノール誘導体の領域選択性およびリングサイズ制御における役割を調査した.

主要な成果:

5〜7つの構成のアザヘテロサイクルとオックスヘテロサイクルを成功裏に製造した.
反応において高い効率と良好な機能群耐性を示した.
キノンメチド中間体による移動を誘導し,リングサイズを制御するフェノールヒドロキシル群の重要な役割を特定した.

結論:

開発されたPd触媒化されたMCARは,ヘテロサイクルの合成のための新しい効率的な戦略を提供します.
この反応は,多様なヘテロサイクルの構造にアクセスするための多用途のプラットフォームを提供します.
キノンメチド中間物質を含むメカニズムを理解することで,サイクロアニュレーションプロセスを正確に制御することができます.

さらに関連する動画

Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-phosphinetriyltripiperidine]}palladium Under Mild Reaction Conditions

Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-phosphinetriyltripiperidine]}palladium Under Mild Reaction Conditions

Published on: March 20, 2014

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

関連する概念動画

[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.

Alkenes via Reductive Coupling of Aldehydes or Ketones: McMurry Reaction

Alkenes via Reductive Coupling of Aldehydes or Ketones: McMurry Reaction

The radical dimerization of ketones or aldehydes gives vicinal diols through a pinacol coupling reaction. However, the behavior of titanium metals used for the reaction as a source of electrons is unusual. When the reaction is carried out in the presence of titanium, diols can be isolated at low temperatures. Else titanium further reacts with diols, forming alkenes through the McMurry reaction.

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.

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.

Cyclohexenones via Michael Addition and Aldol Condensation: The Robinson Annulation

Cyclohexenones via Michael Addition and Aldol Condensation: The Robinson Annulation

Robinson annulation is a base-catalyzed reaction for the synthesis of 2-cyclohexenone derivatives from 1,3-dicarbonyl donors (such as cyclic diketones, β-ketoesters, or β-diketones) and α,β-unsaturated carbonyl acceptors. Named after Sir Robert Robinson, who discovered it, this reaction yields a six-membered ring with three new C–C bonds (two σ bonds and one π bond).

Halogenation of Alkenes

Halogenation of Alkenes

Halogenation is the addition of chlorine or bromine across the double bond in an alkene to yield a vicinal dihalide. The reaction occurs in the presence of inert and non-nucleophilic solvents, such as methylene chloride, chloroform, or carbon tetrachloride.
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.