複合アーレンのサイト選択C−Hアルキル化による2段階のアリルチアントレネーション・リデュークティブ・アルキル化配列
Beatrice Lansbergen1, Paola Granatino1, Tobias Ritter1
1Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm Platz 1, D-45470 Mülheim an der Ruhr, Germany.
Journal of the American Chemical Society
|May 24, 2021
まとめ
新しい2段階のC−Hアルキル化方法を 開発しました このアプローチにより,選択的な後期機能化が可能になり,以前はアクセスできない多様なアルキル化アレンが生成されます.
科学分野:
- 有機化学
- 合成化学
- キャタリシス
背景:
- 薬剤の発見と材料科学にとって 舞台の機能化の後期段階は極めて重要です
- 既存の方法はしばしば選択性が欠けているか,機能化された基板を必要とします.
- 効率的で選択的なCH活性化戦略の開発は,依然として重要な課題です.
研究 の 目的:
- 複雑なアレーンの新しい非誘導パラセレクティブ2段階C−Hアルキル化を提示する.
- 高い選択性と多様性を持つ遅段階の機能化を可能にします.
- 開発されたメソッドの実用性と信頼性を実証する.
主な方法:
- アレンのサイト選択C-Hチアントレネーション
- パラジウム触媒による 還元性電極結合
- 断片結合にチアントレニウムベースの反応剤を使用する.
主要な成果:
- 複合アレンの非誘導パラセレクティブC-Hアルキル化を達成した.
- 合成的に有用なアルキル化アレンの 幅広い範囲にアクセスしました
- 複雑な断片を組み合わせることで 変換の強さを証明した.
結論:
- 提出された方法は,機能化の遅い段階のための実用的で選択的な経路を提供します.
- このC-Hアルキル化戦略は,複雑な分子構造にアクセスするための合成ツールボックスを拡張します.
- ティアントレニウムベースのアプローチは,複雑な断片結合に希望を示しています.
関連する概念動画
02:27Preparation of Alkynes: Alkylation Reaction
11.1K
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.
11.1K
02:24Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
8.3K
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.
8.3K
02:38Electrophilic Addition to Alkynes: Halogenation
9.0K
Introduction
Halogenation is another class of electrophilic addition reactions where a halogen molecule gets added across a π bond. In alkynes, the presence of two π bonds allows for the addition of two equivalents of halogens (bromine or chlorine). The addition of the first halogen molecule forms a trans-dihaloalkene as the major product and the cis isomer as the minor product. Subsequent addition of the second equivalent yields the tetrahalide.
Halogenation is another class of electrophilic addition reactions where a halogen molecule gets added across a π bond. In alkynes, the presence of two π bonds allows for the addition of two equivalents of halogens (bromine or chlorine). The addition of the first halogen molecule forms a trans-dihaloalkene as the major product and the cis isomer as the minor product. Subsequent addition of the second equivalent yields the tetrahalide.
9.0K
01:11Nucleophilic Aromatic Substitution: Elimination–Addition
4.2K
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...
4.2K
02:47Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
19.4K
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.
19.4K
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
3.6K
Catalytic hydrogenation of alkenes is a transition-metal catalyzed reduction of the double bond using molecular hydrogen to give alkanes. The mode of hydrogen addition follows syn stereochemistry.
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
3.6K