的催化不对称的C-H插入 (II) 阿扎维尼尔碳
Stepan Chuprakov1, Jamal A Malik, Mikhail Zibinsky
1The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
Journal of the American Chemical Society
|May 31, 2011
概括
一种新方法使得在未被激活的基中,可以对阿扎维尼尔碳基进行对抗选择性C-H插入. 这种反应通过使用易于获得的前体和性催化剂来功能化C-H键,提供了进入性硫胺胺的途径.
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:
- C-H功能化是有机合成中的一个关键转换.
- 开发用于C-H插入的enantioselective方法仍然是一个挑战.
- 阿扎维尼尔碳为C-H功能化提供了独特的反应性.
研究的目的:
- 开发一种高效的选性C-H插入法,将阿扎维尼尔碳素插入未激活的基中.
- 为了提供一种新的途径,以β-奇拉硫胺.
主要方法:
- 从1-硫-1,2,3-醇直接产生过渡金属碳.
- 使用性Rh(II) 碳酸盐作为催化剂.
- 使用未激活的基因作为基板.
主要成果:
- 实现了高效的酶选择性C-H插入.
- 成功地功能化了未被激活的基的C-H键.
- 合成了各种具有高立体控制的β-基拉硫胺.
结论:
- 已经建立了一种新的,高效的C-H enantioselective功能化的方法.
- 开发的方法提供了直接访问有价值的性硫胺基构建块.
- 这项工作扩大了碳插入反应和C-H激活策略的范围.
相关概念视频
02:24Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
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.
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
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...
01:11Nucleophilic Aromatic Substitution: Elimination–Addition
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01:25Radical Anti-Markovnikov Addition to Alkenes: Overview
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02:35Electrophilic Addition to Alkynes: Hydrohalogenation
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.
02:38Electrophilic Addition to Alkynes: Halogenation
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.