レドックス活性ビス・イミノ・アセナフェン・リガンドクラスのステリカルに誘導された機能化:実験的および理論的調査
Daniel A Evans1, Ignacio Vargas-Baca, Alan H Cowley
1Department of Chemistry and Biochemistry, The University of Texas at Austin , Austin, Texas 78712, United States.
Journal of the American Chemical Society
|September 6, 2013
まとめ
ステリック阻害は,リドックス活性ビス (((イミノ)) アセナフェン (BIAN) リガンドの機能化を指示する. ステル質量に応じて,反応は,急進的脱オロマチゼーションまたは核性アルキル化を経由して進み,新しい合成経路を提供します.
科学分野:
- 有機化学 オーガニック・ケミストリー
- 協調化化学について
- コンピューティング・ケミストリー
背景:
- ビス (((イミノ)) アセナフェン (BIAN) リガンドは,酸化還元活性であり,ステリカルに調節可能である.
- 機能化の経路を理解することは,リガンド設計において極めて重要です.
研究 の 目的:
- Ar-BIANリガンドのステリカルに誘導された機能化を調査する.
- Ar-BIANの機能化の経路のメカニズムを解明する.
主な方法:
- Ar-BIANデリバティブの合成と特徴付け.
- 構造的決定のための単結晶X線 difraktion.
- 反応のモニタリングのための電子パラマグネット共振 (EPR) スペクトロスコーピー.
- 分散型密度関数理論 (DFT-D) は,機械的洞察のための計算を行う.
主要な成果:
- N-C-C-N断片の周りのステリック混雑は,機能化の経路を決定する.
- 2つの異なる経路が特定されました:急性脊髄脱オロマ化と核愛性イミンC-アルキル化.
- 新しいAr-BIAN誘導体の構造 (14-19) は,X線 difraksionによって確認されました.
結論:
- ステリック制御は,Ar-BIANの機能化を指示する重要な要因です.
- DFT-D計算は,観察された反応経路と推進力をうまく説明します.
- この研究は,予測可能な反応性を持つ機能化されたBIANリガンドの設計のための枠組みを提供します.
関連する概念動画
01:19Amines to Amides: Acylation of Amines
Various carboxylic acid derivatives (such as acid chlorides, esters, and anhydrides) can be used for the acylation of amines to yield amides. The reaction requires two equivalents of amines. The first amine molecule functions as a nucleophile and attacks the carbonyl carbon to produce a tetrahedral intermediate. This is followed by the loss of the leaving group and restoration of the C=O bond.
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary amide...
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary amide...
01:11ortho–para-Directing Activators: –CH3, –OH, –NH2, –OCH3
All ortho–para directors, excluding halogens, are activating groups. These groups donate electrons to the ring, making the ring carbons electron-rich. Consequently, the reactivity of the aromatic ring towards electrophilic substitution increases. For instance, the nitration of anisole is about 10,000 times faster than the nitration of benzene. The electron-donating effect of the methoxy group in anisole activates the ortho and para positions on the ring and stabilizes the corresponding...
01:38Preparation of Amines: Reductive Amination of Aldehydes and Ketones
Carbonyl compounds and primary amines undergo reductive amination first to produce imines, followed by secondary amines in the same reaction mixture, using selective reducing agents like sodium cyanoborohydride or sodium triacetoxyborohydride. Reductive amination produces different degrees of substitution of amines depending on the starting amine substrate.
02:34Structural Isomerism
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
01:20Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
Arenediazonium substitution reactions occur when the diazonium group is substituted by various functional groups such as halides, hydroxyl, nitrile, etc. For instance, arenediazonium salts react with copper(I) salts of chloride, bromide, or cyanide to form corresponding aryl chlorides, bromides, and nitriles. These reactions are named Sandmeyer reactions. Although the mechanism of this reaction is complicated, as illustrated in Figure 1, they are believed to progress via an aryl copper...
01:16Aldehydes and Ketones with Amines: Imine and Enamine Formation Overview
Primary amines react with carbonyl compounds—aldehydes and ketones—to generate imines. Imines consist of a C=N double bond and are named Schiff bases after its discoverer—the German chemist Hugo Schiff. On the other hand, secondary amines react with carbonyl compounds to give enamines. In enamines, the presence of a C=C double bond adjacent to the nitrogen atom leads to the delocalization of the lone pair.