((II) -基复合物作为热触发烯水解的"缓释"预催化剂
Sumeng Liu1, Gregory S Girolami1
1School of Chemical Sciences, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois61801, United States.
这项研究引入了一种新的 (II) 催化剂,该催化剂在加热时会变得活跃,从而使极少的副产品具有高度选择性的抗马尔科夫尼科夫化. 这种热触发的延迟使其成为工业应用的理想选择.
科学领域:
- 有机金属化学
- 催化剂
- 材料科学
背景情况:
- 二甲基化合物作为前催化剂进行了研究.
- 现有的催化剂往往缺乏可控激活或表现出副作用.
- 水化是有机合成和材料生产中的关键反应.
研究的目的:
- 合成和描述新的 (II) 二ω-化合物及其添加物.
- 研究这些化合物的催化活性和潜伏时间.
- 了解激活机制并确定潜在的应用.
主要方法:
- (PtR2,R=CH2SiMe2 (乙烯) 或CH2SiMe2 () 复合物的合成和表征.
- 用像1,5-环氧 (COD) 这样的连接物形成添加物.
- 在不同温度下评估催化水活动,选择性和潜伏性.
主要成果:
- 1-COD附加物表现出显著的热触发延迟,在20°C时没有活动,但在50°C时具有很高的周转率 (高达20,000).
- 催化剂对抗马尔科夫尼科夫的产品具有很好的选择性.
- 激活过程是通过缓慢的COD分离,西兰反应和连接物消除,形成活跃的Pt(0) 物种,并减少合的形成.
结论:
- 开发的(II) 预催化剂提供受热触发的控制激活,用于水化.
- 它的高周转率和选择性,加上最小的副产品,是由于活性物种的控制释放.
- 这种预催化剂对注射成型和无溶剂化等工业工艺具有前景.
更多相关视频
09:37Imine Metathesis by Silica-Supported Catalysts Using the Methodology of Surface Organometallic Chemistry
Published on: October 18, 2019
19:58Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions
Published on: July 30, 2017
相关概念视频
Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
Olefin Metathesis Polymerization: Overview
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists...
Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
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.
Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
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...
Reduction of Alkenes: 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...
Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
