Rh2(II) サイクロブタノールで置換されたアリルアジドの触媒式環拡張により,中規模なN-ヘテロサイクルにアクセス
Wrickban Mazumdar1, Navendu Jana1, Bryant T Thurman1
1Department of Chemistry, University of Illinois at Chicago , 845 West Taylor Street, Chicago, Illinois 60607-7061, United States.
Journal of the American Chemical Society
|March 30, 2017
まとめ
研究者らは,中規模の窒素ヘテロサイクルを合成するための新しいロジウム触媒反応を発見した. この方法は,オルト・サイクロブタノールで置換されたアリルアジドを使用し,非常に選択的なリング拡張ステップを特徴としています.
科学分野:
- 有機化学
- カタリシス
- 合成方法論
背景:
- 窒素ヘテロサイクルは,医薬品化学と材料科学における重要な基幹である.
- 中型ヘテロサイクルの効率的な合成は,有機合成における重要な課題です.
- ロジウム触媒反応は,C-N結合形成とヘテロサイクル合成のための強力なツールを提供します.
研究 の 目的:
- ロジウム (II) -N-アリルニトレンの新しい反応パターンを発見する.
- 中型窒素ヘテロサイクルの新合成経路を開発する.
- キーリングの拡張ステップのメカニズムを解明する.
主な方法:
- オルト・サイクロブタノールで代替されたアリルアジドを原料として使用する.
- ロジウム (II) 触媒を用いて,N-アリルニートレンの中間物質を生成する.
- 機械的な実験を通して反応経路を調査する.
主要な成果:
- Rh ((II) - N- アリルニトレンの新しい反応パターンが特定されました.
- 中規模のN-ヘテロサイクルの触媒合成が達成された.
- 鍵となる環膨張のステップは,化学選択性およびステレオ特異性であることが示された.
- 機械学的研究により,競争的な sp3 C-H 結合アミネーションが示された.
結論:
- 発見された反応性は,中規模のN-ヘテロサイクルの効率的な合成を可能にします.
- 触媒サイクルには,ロジウムN-アリルニトレンの中間物質が含まれています.
- C-Hアミネーションのような競合する経路を理解することは,反応を最適化するための鍵です.
さらに関連する動画
関連する概念動画
Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
21.6K
Introduction
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
21.6K
Cyclohexenones via Michael Addition and Aldol Condensation: The Robinson Annulation
3.0K
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).
3.0K
Nucleophilic Aromatic Substitution: Elimination–Addition
5.3K
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...
5.3K
Cycloaddition Reactions: Overview
3.7K
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.
3.7K
Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
2.6K
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...
2.6K
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
13.1K
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.
13.1K


