停止催化:通过氧化还原活性N- heterocyclic carbene控制Kumada合活性
Andrew G Tennyson1, Vincent M Lynch, Christopher W Bielawski
1Department of Chemistry and Biochemistry, The University of Texas at Austin, 1 University Station A5300, Austin, Texas 78712, USA.
Journal of the American Chemical Society
|June 22, 2010
概括
优化了纳夫托基尼米达化物及其银-NHC复合物的合成. 这些复合物有效地形成10组金属化合物,在库马达交叉合反应中表现出氧化还原切换催化活性.
科学领域:
- 有机金属化学 有机金属化学
- 催化剂是一种催化剂.
- 协调化学 协调化学
背景情况:
- 在有机金属化学中,N-异环碳 (NHCs) 是多功能联体.
- 开发NHC前体及其金属复合物的高效合成对于催化应用至关重要.
研究的目的:
- 为了优化1,3-dimesitylnaphthoquinimidazolium化物及其银复合物的合成.
- 用这个NHC连接体合成和表征第10组金属复合物 (Ni,Pd,Pt).
- 研究这些新型复合物的电化学特性和催化活性.
主要方法:
- 优化了NHC前体和银-NHC复合物的合成.
- 转金属化反应形成Ni,Pd和Pt复合体.
- 电化学测量 (循环电压测量,光谱电化学).
- 在Kumada交叉合反应中进行催化试验.
主要成果:
- 对于NHC前体和银复合物实现了近乎定量的产量.
- 10组金属复合物的高产量 (>95%) 通过转移.
- 电化学数据表明金属独立的子降解潜力.
- 复杂的3a催化库马达合;活性可以通过氧化还原剂 (cobaltocene,ferrocenium tetrafluoroborate) 调节.
- 证明了催化剂在减少/无活性状态中的稳定性和氧化后的活性.
结论:
- 建立了有效的合成路径,以获得新的NHC-Group 10复合体.
- 这些复合体通过氧化还原切换表现出可调节的催化活性.
- 这些发现提供了对交叉合反应的催化剂设计的见解.
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