トリアゾール・ゴールド触媒によるアルキンの分子間ホモプロパルギルアルコールの添加と連続的な1,6-エニンのサイクロイソメリゼーション
Seyedmorteza Hosseyni1, Lukasz Wojtas1, Minyong Li2
1Department of Chemistry, University of South Florida , Tampa, Florida 33620, United States.
Journal of the American Chemical Society
|March 10, 2016
まとめ
新しいトリアゾール・ゴールド触媒は,分子間アルキン添加とユニークな1,6-エニンサイクロイソメリゼーションを容易にし,ジヒドロキセピンを生成しました. その後の反応により,高いステレオ選択性を持つヒドロベンゾフランが生成され,1つのステップで5つのステレオセンターが生成された.
科学分野:
- 有機化学
- カタリシス
- 合成方法論
背景:
- ホモプロパルギルアルコールの黄金触媒サイクルが確立された.
- 端末アルキンによって,分子内循環が妨げられる.
研究 の 目的:
- ホモプロパルギルアルコールの反応のための新しいトリアゾール・ゴールドの触媒を探求する.
- 複雑な有機分子のための 新しい合成経路を開発する
主な方法:
- ホモプロパルギルアルコールの変換にトリアゾール・ゴールドの触媒を使用した.
- 連続的な1,6-エニンサイクロイソメリゼーションを調査した.
- ディエルス・アルダー反応と1,3-アルコキシルシフトを実行した.
主要な成果:
- アルキンへの分子間添加が達成され,分子内循環が防止されます.
- 1,6-エニンサイクロイソメリゼーションにより,異常な2,3-ジヒドロキセピンを合成した.
- 新しい反応のカスケードによって,高収量でヒドロベンゾフーランの誘導体を得ている.
- 優れたエナチオ選択性を持つ5つのステレオセンターのダイアステレオ選択的形成が実証された.
結論:
- トリアゾール・ゴールドの触媒は 独特の分子間添加とサイクロイソメリゼーションを可能にします
- ホモプロパルギルアルコールからヒドロベンゾフランを合成する新たな経路が確立された.
- 複雑なステレオセンターの効率的な構築を可能にします.
関連する概念動画
02:47Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
21.8K
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.
21.8K
02:35Electrophilic Addition to Alkynes: Hydrohalogenation
12.0K
Electrophilic addition of hydrogen halides, HX (X = Cl, Br or I) to alkenes forms alkyl halides as per Markovnikov's rule, where the hydrogen gets added to the less substituted carbon of the double bond. Hydrohalogenation of alkynes takes place in a similar manner, with the first addition of HX forming a vinyl halide and the second giving a geminal dihalide.
12.0K
02:27Preparation of Alkynes: Alkylation Reaction
12.6K
Introduction
Alkylation of terminal alkynes with primary alkyl halides in the presence of a strong base like sodium amide is one of the common methods for the synthesis of longer carbon-chain alkynes. For example, treatment of 1-propyne with sodium amide followed by reaction with ethyl bromide yields 2-pentyne.
Alkylation of terminal alkynes with primary alkyl halides in the presence of a strong base like sodium amide is one of the common methods for the synthesis of longer carbon-chain alkynes. For example, treatment of 1-propyne with sodium amide followed by reaction with ethyl bromide yields 2-pentyne.
12.6K
02:24Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
9.4K
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.
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.
9.4K
02:15Preparation of Alcohols via Addition Reactions
8.1K
Overview
The acid-catalyzed addition of water to the double bond of alkenes is a large-scale industrial method used to synthesize low-molecular-weight alcohols. An acidic atmosphere is required to allow the hydrogen in the water molecule to act as an electrophile and attack the double bond in an alkene. The addition of a proton to the double bond creates a carbocation intermediate. The proton preferentially bonds to the less substituted end of the double bond to create a more stable carbocation...
The acid-catalyzed addition of water to the double bond of alkenes is a large-scale industrial method used to synthesize low-molecular-weight alcohols. An acidic atmosphere is required to allow the hydrogen in the water molecule to act as an electrophile and attack the double bond in an alkene. The addition of a proton to the double bond creates a carbocation intermediate. The proton preferentially bonds to the less substituted end of the double bond to create a more stable carbocation...
8.1K
02:40Alkynes to Aldehydes and Ketones: Acid-Catalyzed Hydration
11.3K
Introduction
Analogous to alkenes, alkynes also undergo acid-catalyzed hydration. While the addition of water to an alkene gives an alcohol, hydration of alkynes produces different products such as aldehydes and ketones.
Analogous to alkenes, alkynes also undergo acid-catalyzed hydration. While the addition of water to an alkene gives an alcohol, hydration of alkynes produces different products such as aldehydes and ketones.
11.3K