阿尔基尼尔-普林斯维尼尔碳酸盐的原始方面,用于非活化的C-H键的功能化:高度选择性的[1,5]-化物迁移与[1,5]-化物迁移. 有关的C-H插入
Surabhi Mishra1, Debayan Roy1, Beeraiah Baire1
1Indian Institute of Technology Madras, Chennai-600036, Tamil Nadu, India.
Organic letters
|November 20, 2025
概括
这项研究引入了一种新的多米诺过程,用于选择性C(sp3) -H键的功能化,使用alkynyl-Prins乙烯基carbocations. 该方法有效地合成了具有高区域选择性和立体选择性的复杂多环桥系统.
科学领域:
- 有机化学 有机化学
- 催化剂是一种催化剂.
- 合成方法论 合成方法论
背景情况:
- 选择性功能化不活化的C ((sp3) -H键是至关重要的,但由于分子内的类似键类型,具有挑战性.
- 当前的方法在准特定的C(sp3) -H键时,经常与区域选择性和立体选择性作斗争.
研究的目的:
- 开发一种前所未有的多米诺进程,用于选择性功能化非活化的C(sp3) -H债券.
- 为了利用alkynyl-Prins乙烯基碳酸作为这一转化过程的关键中间体.
- 为了实现多种多环桥系统的高效合成.
主要方法:
- 采用了一种多米诺反应策略,涉及基尼尔-普林斯乙烯基碳酸盐.
- 使用三酸 (TfOH) 作为小分子催化剂.
- 研究了二级 (sec) 和三级 (tert) C-H 键之间的区域选择性,以及二元体 C-H 键之间的立体选择性.
主要成果:
- 实现了对多种多环桥系统的快速和高效访问.
- 证明了高的区域选择性 (sec-C-H与tert-C-H) 和立体选择性 (二元立体的C-H键).
- 提供了支持[1,5]-化物迁移而不是通过中间捕获进行协同的C-H插入的机制证据.
结论:
- 开发的多米诺过程为C ((sp3) -H功能化提供了一个强大的新工具.
- 该策略可以通过1C-O和2C-C键形成来构建复杂的分子架构.
- 这项工作推进了选择性C-H激活和合成多环化合物的领域.
相关概念视频
02:38Electrophilic Addition to Alkynes: Halogenation
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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.
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02:17Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule
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If a set of reactants can yield multiple constitutional isomers, but one of the isomers is obtained as the major product, the reaction is said to be regioselective. In such reactions, bond formation or breaking is favored at one reaction site over others.
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...
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02:35Electrophilic Addition to Alkynes: Hydrohalogenation
11.3K
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.
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02:34Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration
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The rate of acid-catalyzed hydration of alkenes depends on the alkene's structure, as the presence of alkyl substituents at the double bond can significantly influence the rate.
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02:24Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
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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.
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01:38Preparation of Alcohols via Substitution Reactions
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Overview
Alcohols can be synthesized from alkyl halides via nucleophilic substitution reactions. The highly polar carbon-halogen bond in the substrate makes halide a good leaving group. The hydroxide ion or water can act as a nucleophile to take the place of halide and form an alcohol. The substitution reactions occur via two different reaction pathways, SN1 or SN2, depending on the nature of carbon attached to the halide.
Primary alcohols are synthesized from primary alkyl halides, and the...
Alcohols can be synthesized from alkyl halides via nucleophilic substitution reactions. The highly polar carbon-halogen bond in the substrate makes halide a good leaving group. The hydroxide ion or water can act as a nucleophile to take the place of halide and form an alcohol. The substitution reactions occur via two different reaction pathways, SN1 or SN2, depending on the nature of carbon attached to the halide.
Primary alcohols are synthesized from primary alkyl halides, and the...
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