催化地选择性化未激活的C ((sp3) -H键
Xuesong Wu1, Yan Zhao, Haibo Ge
1Department of Chemistry and Chemical Biology, Indiana University Purdue University Indianapolis , Indianapolis, Indiana 46202 United States.
Journal of the American Chemical Society
|January 23, 2014
概括
催化直接化未被激活的sp(3) 酸胺中C-H键. 这种方法优先针对甲基而不是甲基,证明了对高效化学合成的广泛功能组耐受性.
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:
- 在有机合成中,未被激活的sp(3) C-H键的直接功能化仍然是一个重大挑战.
- 亚利法胺是药品和材料中普遍存在的结构图案.
- 开发用于胺C-H键激活的选择性和高效的方法是非常可取的.
研究的目的:
- 开发一种新的催化方法,用于直接化未激活的sp(3) C-H键在亚利法性胺中.
- 调查反应对不同类型的C-H键 (甲基与甲) 和功能组的选择性.
- 阐明反应机制,包括指导组的作用和循环金属化步骤.
主要方法:
- 催化直接化,使用双酸导向组.
- 采用各种具有多种功能组的各种异形胺基.
- 机械学研究涉及中间分析和计算建模.
主要成果:
- 成功地直接化了非激活的sp(3) C-H键的阿里法胺.
- 反应显示出甲基C-H键对甲基C-H键的强烈偏好.
- 多种功能组被容忍,突出显示了反应的稳定性.
- 机理学研究表明,一个五个环的中间体在指导基的sp{2) C-H键的选择性方面发挥着关键作用.
结论:
- 已经建立了一种新的高效的催化直接化阿里法胺sp(3) C-H键.
- 该方法为甲基C-H键提供了高选择性和广泛的功能组兼容性.
- 这项工作为合成含有功能化胺分子的复杂分子提供了有价值的新工具.
相关概念视频
02:27Preparation of Alkynes: Alkylation Reaction
9.4K
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.
9.4K
02:24Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
6.9K
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.
6.9K
02:38Electrophilic Addition to Alkynes: Halogenation
7.4K
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.
7.4K
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
2.6K
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...
2.6K
01:10α-Alkylation of Ketones via Enolate Ions
2.4K
Ketones with α protons are deprotonated by strong bases like lithium diisopropylamide (LDA) to form enolate ions. The anion is stabilized by resonance, and its hybrid structure exhibits negative charges on the carbonyl oxygen and the α carbon. This ambident nucleophile can attack an electrophile via two possible sites: the carbonyl oxygen, known as O-attack, or the α carbon, known as C-attack. The nucleophilic attack via the carbanionic site is preferred. This is due to the...
2.4K
02:17Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule
14.2K
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...
14.2K