催化剂控制的化
在PubMed上查看摘要
概括
此摘要是机器生成的。这项研究报告了一种新方法,用于抗生素thio- strepton的部位和立体选择性化. 研究人员开发了受联体控制的方法来选择性地化脱氨酸残留物,产生具有改变抗生素活性的新衍生物.
科学领域
- 有机化学
- 医学化学
- 催化剂
背景情况
- 斯特是一种复杂的抗生素,具有独特的脱氨酸 (Dha) 尾部.
- 控制Dha残留的选择性减少是具有挑战性的,但对于修改抗生素活性至关重要.
研究的目的
- 开发石的位点和立体选择性化方法.
- 合成具有修饰抗生素特性的新型列衍生物.
- 调查特定的Dha残留物在列的生物活性中的作用.
主要方法
- 使用单酸胺联体 (例如MonoPhos) 进行对称的化.
- 在温和条件下选择性化二聚烯尾部碎片.
- 使用硬质减弱的胺基体对内部脱氨酸残留物 (Dha3) 进行化.
- 使用双酸连体对四化产品进行化.
- 通过NMR光谱和X射线晶体学进行结构和立体化学阐明.
主要成果
- 在使用MonoPhos配体的双化 bis ((Dha) 化合物中获得高选择性 (> 96%).
- 对于化列尾部碎片,已证明其列选择性高于80%.
- 成功化了性阻碍的Dha3残留物,其性决定了立体化学结果.
- 合成了不同的二,三和四三衍生物.
- 确定了Dha化对抗生素活性对抗耐药细菌菌株的显著影响.
结论
- 开发了多功能,受联体控制的化策略.
- 确立了Dha3残留物在硫的抗生素有效性中的关键作用.
- 合成的衍生品代表了新抗生素开发的前途.
相关概念视频
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...
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.
Thermodynamic Stability
Catalytic hydrogenation reactions help evaluate the relative thermodynamic stability of hydrocarbons. For example, the heat of hydrogenation of acetylene is −176 kJ/mol, and that of ethylene is −137 kJ/mol. The higher exothermicity...
Alkenes undergo reduction by the addition of molecular hydrogen to give alkanes. Because the process generally occurs in the presence of a transition-metal catalyst, the reaction is called catalytic hydrogenation.
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the...
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...
Unlike the easy catalytic hydrogenation of an alkene double bond, hydrogenation of a benzene double bond under similar reaction conditions does not take place easily. For example, in the reduction of stilbene, the benzene ring remains unaffected while the alkene bond gets reduced. Hydrogenation of an alkene double bond is exothermic and a favorable process. In contrast, to hydrogenate the first unsaturated bond of benzene, an energy input is needed; that is, the process is endothermic. This is...
The conversion of allylic alcohols into epoxides using the chiral catalyst was discovered by K. Barry Sharpless and is known as Sharpless epoxidation. The use of a chiral catalyst enables the formation of one enantiomer of the product in excess. This chiral catalyst is mainly a chiral complex of titanium tetraisopropoxide and tartrate ester (specific stereoisomer). The stereoisomer used in the chiral catalyst dictates the formation of the enantiomer of the product. In other words, the use of...

