フェノールやアニリンとアリル鉛トリアセテートとの非対称的な炭素-炭素結合
Taichi Kano1, Yuki Ohyabu, Susumu Saito
1Contribution from the Graduate School of Engineering, Nagoya University, SORST, Japan.
Journal of the American Chemical Society
|May 9, 2002
まとめ
この研究では,キラルアミンと有機金属反応剤を用いたフェノールとアニリンの非対称結合について詳細に説明しています. 開発された方法は,低温で高選択性で軸性キラルポリアリル化合物を効率的に生成します.
科学分野:
- 有機化学 オーガニック・ケミストリー
- アシンメトリック・シンセシス
- カタリシス カタリシス カタリシス
背景:
- 軸性キラルバイアリル化合物は,様々な分野における重要な構成要素である.
- それらの合成のための効率的で選択的な方法の開発は,依然として課題です.
研究 の 目的:
- フェノールおよびアニリン誘導体のアリル鉛トリアセテートとの非対称な結合を調査する.
- 多様な軸性キラルポリアリル化合物を合成するための効率的な方法を開発する.
主な方法:
- キラル補助剤として光学的に活性なアミン (ストリヒニン,ブルシン) を利用した.
- 構成制限のある三次アミン,リチウムアロキシド,フェノール結合のための分子を用いる.
- アリル鉛トリアセテートとのアニリン結合のための応用マグネゼーション.
主要な成果:
- 低温 (-40 °Cから -20 °C) でフェノール結合で高いダイアステロ選択性とエナチオ選択性を達成した.
- アニリン結合の鍵となる技術としてマグネゼーションを確立した.
- 軸性キラリティを持つ多種多様な二,三,ポリアリル化合物を成功裏に合成した.
結論:
- 軸性キラルポリアリル化合物の非対称合成のための堅牢で選択的な方法を開発しました.
- 合成された化合物は,金属リガンド,天然製品,および螺旋型ポリマーの貴重な前駆体です.
関連する概念動画
01:28Structures of Carboxylic Acid Derivatives
Structure of Carboxylic Acid Derivatives
Carboxylic acid derivatives contain an acyl group attached to a heteroatom such as chlorine, oxygen, or nitrogen. The carbonyl carbon and oxygen are both sp2-hybridized with an unhybridized p orbital.
The three sp2 orbitals of the carbonyl carbon form three σ bonds, one each with the carbonyl oxygen, the α carbon, and the heteroatom, whereas the other two sp2 orbitals of the carbonyl oxygen are occupied by the lone pairs. Further, the unhybridized p...
Carboxylic acid derivatives contain an acyl group attached to a heteroatom such as chlorine, oxygen, or nitrogen. The carbonyl carbon and oxygen are both sp2-hybridized with an unhybridized p orbital.
The three sp2 orbitals of the carbonyl carbon form three σ bonds, one each with the carbonyl oxygen, the α carbon, and the heteroatom, whereas the other two sp2 orbitals of the carbonyl oxygen are occupied by the lone pairs. Further, the unhybridized p...
01:07Acid Halides to Amides: Aminolysis
Aminolysis is a nucleophilic acyl substitution reaction, where ammonia or amines act as nucleophiles to give the substitution product. Acid halides react with ammonia, primary amines, and secondary amines to yield primary, secondary, and tertiary amides, respectively.
In the first step of the aminolysis mechanism, the amine attacks the carbonyl carbon of the acyl chloride to form a tetrahedral intermediate. In the second step, the carbonyl group is re-formed with the elimination of a chloride...
In the first step of the aminolysis mechanism, the amine attacks the carbonyl carbon of the acyl chloride to form a tetrahedral intermediate. In the second step, the carbonyl group is re-formed with the elimination of a chloride...
01:19Reactions of Acid Anhydrides
The reactions of acid anhydrides are analogous to the reactions of acid chlorides and proceed via a nucleophilic acyl substitution. They only differ in the identity of the leaving group. During an acid chloride reaction, the leaving group is a chloride ion, and the by-product is hydrochloric acid. However, in an acid anhydride reaction, the leaving group is a carboxylate ion, and the by-product is a carboxylic acid.
01:19Structure of Amines
The hybridized nitrogen atom in amines possesses a lone pair of electrons and is bound to three substituents with a bond angle of around 108°, which is less than the tetrahedral angle of 109.5°. However, the C–N–H bond angle is slightly larger at 112°, with a carbon–nitrogen bond length of 147 pm. This carbon–nitrogen bond length of of amines is longer than the carbon–oxygen bond of alcohols (143 pm) but shorter than alkanes’ carbon–carbon bond (154 pm). These aspects are illustrated in Figure...
01:11Nomenclature of Carboxylic Acid Derivatives: Amides and Nitriles
Naming Amides
The IUPAC and common names of amides are derived from the parent carboxylic acid, by replacing the suffix “oic acid” and “ic acid,” respectively, with “amide.” In the following example, the IUPAC name ethanamide is derived from ethanoic acid, and the common name, acetamide, is obtained from acetic acid.
The IUPAC and common names of amides are derived from the parent carboxylic acid, by replacing the suffix “oic acid” and “ic acid,” respectively, with “amide.” In the following example, the IUPAC name ethanamide is derived from ethanoic acid, and the common name, acetamide, is obtained from acetic acid.
01:10Nomenclature of Aryl and Heterocyclic Amines
The simplest aromatic amine is phenylamine, which contains an –NH2 functionality directly attached to an aromatic ring. The name aniline is designated for this skeleton. As shown in Figure 1, the common names of the functionalized anilines involve prefixes ortho-, meta-, and para- to indicate the substitution position. Different functionalized aniline derivatives also have notable trivial names.