选择性烯寡合化的哈夫诺催化剂:通过β-甲基转移有效合成4-甲基-1-
Yasuhiko Suzuki1, Takahiro Yasumoto, Kazushi Mashima
1Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, D-52074 Aachen, Germany.
哈夫诺复合物有效催化烯二聚变为4-甲基-1-,选择性受到连接物替代物的影响. 立体阻碍的配体和特定的反应条件优化了4-甲基-1-的产生,而其他复合物则表现出聚合或快速失活.
科学领域:
- 有机金属化学 有机金属化学
- 聚合物科学 聚合物科学
- 催化剂是一种催化剂.
背景情况:
- 哈夫诺复合物被探索为烯的寡合化.
- 了解连接体对催化剂性能的影响对于选择性合成至关重要.
研究的目的:
- 合成和评估一系列的哈夫诺复合物作为烯寡合化催化剂.
- 调查环丁乙烯连接物替代剂对催化活性和选择性的影响.
主要方法:
- 用不同的R1和R2替代剂合成哈夫诺复合物.
- 使用甲基氨酸 (MAO) 或[Ph3C][B(C6F5)4]/Al(i) Bu3激活的烯寡合化.
- 通过气相色谱和副产品分布分析进行产品分析.
- 随机模拟模型反应动力学.
主要成果:
- 复合体 2-4 和 8-12 催化了烯二聚化到4-甲基-1-烯,选择性高达61.6%的重量%.
- 对4-甲基-1-烯的最高选择性是通过 (eta5-C5Me4(i) Bu) 2HfCl2 (12) 实现的.
- 复合物1聚合了烯,而复合物5-7显示出快速的失活.
- 产品分布和反应速率取决于配体结构和反应条件.
结论:
- 连接物结构显著影响烯氧化聚合物中的哈夫诺催化剂选择性.
- 环二烯联体的固体质量会影响终结途径和产品的分布.
- 优化反应条件和催化剂设计可以有利于选择性二分化到4-甲基-1-.
更多相关视频
08:25Development of Heterogeneous Enantioselective Catalysts using Chiral Metal-Organic Frameworks MOFs
Published on: January 17, 2020
12:08Catalytic Reactions at Amine-Stabilized and Ligand-Free Platinum Nanoparticles Supported on Titania During Hydrogenation of Alkenes and Aldehydes
Published on: June 24, 2022
相关概念视频
Regioselectivity of Electrophilic Additions-Peroxide Effect
Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration
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...
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 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.
Olefin Metathesis Polymerization: Overview
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists of a...
