对类的转合添加:因化化的案例
Frédéric Guégan1,2, Fabrice Chemla3, Franck Ferreira3
1Sorbonne Université, CNRS, Laboratoire de Chimie Théorique, LCT, F-75005, Paris, France.
Chemistry (Weinheim an der Bergstrasse, Germany)
|May 29, 2024
概括
这项研究揭示了一种协同的面间机制,用于添加西-到 ynamides,通过DFT计算解释观察到的区域和立体选择性.
科学领域:
- 有机金属化学 有机金属化学
- 计算化学计算化学
- 有机合成 有机合成
背景情况:
- 了解有机金属试剂的反应机制对于合成化学至关重要.
- 亚纳米德是有机合成中的多功能构建块.
- 甲基-试剂具有独特的反应性概况.
研究的目的:
- 通过计算来研究添加到 ynamides 的二甲基-试剂的机制.
- 阐明控制观察到的区域选择性和立体选择性的因素.
- 根据实验数据验证拟议的协调面部间机制.
主要方法:
- 用密度函数理论 (DFT) 的计算来建模反应路径.
- 激活菌株模型 (ASM) 用于分析过渡状态.
- 化学结合分析为电子结构变化提供了洞察力.
主要成果:
- 一个协调的面部间机制被确定为能量偏好的途径.
- 涉及 η2-乙烯中间体或基因通路的替代机制被认为是不可持续的.
- DFT计算准确地重现了实验区域选择性 (有利于西β添加) 和立体选择性 (取决于试剂的cis或trans).
结论:
- 协调的面膜间机制是对被观察到的二甲基-试剂与 ynamides 的反应性的强有力的解释.
- DFT计算是预测和理解这种有机金属转换中的选择性的可靠工具.
- 这项研究为合成功能化乙烯基纤维素提供了更深入的机制理解.
相关概念视频
02:38Electrophilic Addition to Alkynes: Halogenation
8.2K
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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02:27Preparation of Alkynes: Alkylation Reaction
10.1K
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.
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02:35Electrophilic Addition to Alkynes: Hydrohalogenation
9.9K
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9.9K
02:34Preparation of Alkynes: Dehydrohalogenation
15.8K
Introduction
Alkynes can be prepared by dehydrohalogenation of vicinal or geminal dihalides in the presence of a strong base like sodium amide in liquid ammonia. The reaction proceeds with the loss of two equivalents of hydrogen halide (HX) via two successive E2 elimination reactions.
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02:24Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
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Introduction
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01:09Conjugate Addition to α,β-Unsaturated Carbonyl Compounds
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