関連する実験動画
Updated: Jul 13, 2026

10:15
Multiplex PCR and Reverse Line Blot Hybridization Assay (mPCR/RLB)
Published on: August 6, 2011
モノオルガノチン反応剤を用いた非活性化された二次アルキルハリドの静かなクロスカップリング
David A Powell1, Toshihide Maki, Gregory C Fu
1Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Journal of the American Chemical Society
|January 13, 2005
まとめ
新しいニッケルベースの触媒は,二次アルキルハリドの静かな交互結合を可能にし,有機合成の重要な進歩です. この方法は,費用対効果の高いコンポーネントとモノオルガノチン反応剤を使用して,有毒な副産物を防止し,よりグリーンな代替品を提供します.
科学分野:
- 有機化学 オーガニック・ケミストリー
- カタリシス カタリシス カタリシス
- 有機金属化学 有機金属化学
背景:
- 静かなクロスカップリング反応は,有機合成における炭素-炭素結合形成に不可欠である.
- 以前の方法は,二次アルキルハリドを効果的にカップリングする能力が限られていた.
- トライオルガノチンの有毒な副産物の生成は,浄化と環境の安全性において重大な課題をもたらした.
研究 の 目的:
- 二次アルキルハリドと静かなクロスカップリングを行うことができる最初の触媒を開発する.
- より効率的で,費用対効果が高く,環境に悪影響のないStilleカップリングプロトコルの確立.
- 危険なトライオルガノチン副産物の形成を回避するために.
主な方法:
- ニッケル (ニッケル) 塩化物 (NiCl2) と2,2'-ビピリジンを使用した新しい触媒システムの開発.
- モノオルガノチン反応剤をクロスカップリング反応で使用する.
- 主要および二次アルキルハリドの結合のための反応条件の最適化.
主要な成果:
- 第1回,二次アルキルハリドのスティルクロスカップリングを成功裏に達成しました.
- 触媒システムは,高い効率と広範な適用性を実証しました.
- モノオルガノチン反応剤の使用は,有毒なトライオルガノチン化合物の形成を効果的に排除しました.
- 安価で簡単に取り扱える触媒部品を使用した.
結論:
- 開発されたニッケルベースの触媒は,二次アルキルハリドの使用を可能にする,静止クロスカップリング化学の画期的な進展を表しています.
- この方法は,既存のプロトコルに対して,実用的で,経済的で,より安全な代替手段を提供します.
- 有毒な副産物を避けることで,合成プロセスの持続可能性が向上します.
関連する概念動画
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 halogen to form a...
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 halogen to form a...
Base-Promoted α-Halogenation of Aldehydes and Ketones
α-Halogenation of aldehydes and ketones is a reaction involving the substitution of α hydrogens with halogens in the presence of a base. The reaction begins with the abstraction of α hydrogen by the base to produce a nucleophilic enolate ion. This intermediate undergoes a subsequent nucleophilic substitution with the halogen to produce a monohalogenated carbonyl compound. If the starting substrate has more than one α hydrogen, it is difficult to stop the reaction at the stage of...
Crossed Aldol Reaction Using Weak Bases
This lesson deals with the crossed aldol reaction using weak bases. The self-condensation of an aldehyde having α hydrogen is prevented by adding it slowly to a mixture of formaldehyde and weak bases like hydroxide and alkoxide. Upon slow addition of the aldehyde, the base deprotonates the α carbon of the aldehyde to form the corresponding enolate. The enolate subsequently attacks the formaldehyde to form a single crossed product. Figure 1 depicts the aforementioned reaction.
Nucleophilic Aromatic Substitution: Elimination–Addition
Simple aryl halides do not react with nucleophiles. However, nucleophilic aromatic substitutions can be forced under certain conditions, such as high temperatures or strong bases. The mechanism of substitution under such conditions involves the highly unstable and reactive benzyne intermediate. Benzyne contains equivalent carbon centers at both ends of the triple bond, each of which is equally susceptible to nucleophilic attack. This 50–50 distribution of products is confirmed through isotopic...
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.
Crossed Aldol Reactions: Overview
Crossed aldol addition is the reaction between two different carbonyl compounds under acidic or basic conditions. Here, both the carbonyl compounds function as nucleophiles and electrophiles. As shown in Figure 1, such a reaction yields a mixture of products, two of which are formed via self-condensation, while the remaining two are formed via crossed-condensation. Without adjustment, the reaction's usefulness in organic chemistry is decreased.

