对于高效的Pd催化替代反应而言,新的酸盐-氧化联体
Oscar Pàmies1, Montserrat Diéguez, Carmen Claver
1Universitat Rovitat i Virgili, Departament de Química Física i Inorgànica, C/ Marcel.lí Domingo s/n., 43007 Tarragona, Spain. oscar.pamies@urv.net
Journal of the American Chemical Society
|March 18, 2005
概括
研究人员为催化反应开发了新的酸盐-氧化连接物. 这些配体使得高效和选择性的不对称基替代成为可能,实现了优异的产量和广泛的基质范围.
科学领域:
- 有机金属化学 有机金属化学
- 不对称的催化剂.
背景情况:
- 催化不对称的基替代是有机合成中的关键反应.
- 开发高效和选择性的配体是改善这些转换的关键.
研究的目的:
- 设计和合成一个新的模块化酸盐-氧化素连接体家族.
- 为了评估这些配体在Pd催化不对称的基替代反应中的有效性.
主要方法:
- 涉及酸盐-氧化框架的联结体合成.
- 使用新联体的催化不对称的基替代反应.
- 分析反应速率 (周转频率,TOF) 和酶选择性 (EE).
主要成果:
- 新的连接物系列显示出出色的反应速率,TOF超过2400mol. (莫升小时) - - 1.
- 获得了高的enantioselectivities,高达>99% ee.
- 带表现出广泛的基质范围,表明了多功能性.
结论:
- 设计的酸盐-氧沙林配体对于Pd催化不对称的基替代是非常有效的.
- 加入一个pi受体双酸部分对反应结果有益.
- 这种联体家族为高效和选择性合成提供了一个有前途的平台.
相关概念视频
Catalysis
The presence of a catalyst affects the rate of a chemical reaction. A catalyst is a substance that can increase the reaction rate without being consumed during the process. A basic comprehension of a catalysts’ role during chemical reactions can be understood from the concept of reaction mechanisms and energy diagrams.
Carboxylic Acids to Acid Chlorides
Carboxylic acids react with SOCl2 or PCl5 to form acid chlorides. Amongst the carboxylic acid derivatives, acid chlorides are the most reactive and synthetically important derivatives. They are useful reagents for Friedel–Crafts acylation of some aromatic compounds.
Types of Reversible Electrodes
For electrode reversibility to be maintained, all the reactants and products involved in the half-reaction must be present at the electrode. There are several types of reversible electrodes (half-cells).In metal-metal-ion electrodes, a metal balances electrochemically with a solution of its own ions. Examples are Cu2+|Cu and Zn2+|Zn. Metals that react with the solvent, like group 1 and most group 2 metals, which react with water, and zinc, which reacts with aqueous acidic solutions, cannot be...
Catalysis
Catalysis influences the rate of chemical reactions by providing an alternative reaction pathway with lower activation energy. A catalyst speeds up a reaction, but it is not consumed during the process. The fundamental principle of catalysis is the ability of a catalyst to alter the reaction mechanism, often introducing a more efficient pathway than the uncatalyzed process.In a catalyzed reaction, the catalyst participates directly in the reaction mechanism. It interacts with reactants to form...
Heterogeneous Catalysis
Heterogeneous catalysis involves a catalyst in a different phase from the reactants. It is a process where the catalyst and the reactants are in distinct phases, typically solid and gas or liquid.Most heterogeneous catalysts are metals, metal oxides, or acids. The list includes transition metals like iron (Fe), cobalt (Co), nickel (Ni), palladium (Pd), platinum (Pt), chromium (Cr), manganese (Mn), tungsten (W), silver (Ag), and copper (Cu). These metals possess partially vacant d orbitals that...
Leveling Effect
In acid-base chemistry, the leveling effect refers to the limitation imposed by the solvent on the strength of acids and bases in solution. When a base stronger than the solvent's conjugate base is used, it deprotonates the solvent until the base is entirely consumed, making it ineffective against weaker acids. Conversely, an acid stronger than the solvent's conjugate acid protonates the solvent until the acid is depleted, rendering it ineffective against weaker bases. Essentially, the solvent...


