Synergistic Ligand Effects in Palladium Catalysis

钯催化中的协同配体效应

• 批准号: EP/H012737/1
• 负责人: Catherine Cazin
• 金额: $ 12.81万
• 依托单位: University of St Andrews
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2009
• 资助国家: 英国
• 起止时间: 2009 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FH012737%2F1
• 关键词: Synergistic; Ligand; Effects; Palladium; Catalysis

The role of ligands, as transition-metal complex modifiers, is fundamental in organometallic chemistry and catalysis. These ancillary, often called spectator , ligands have a profound influence on catalyst activity and longevity. In this proposal, very specific ligand classes, namely the classical P-donors (PR3, P(OR)3, PR(OR)2, P(R2(OR)) in combination with the more recently employed and developed N-Heterocyclic carbenes (NHC) are proposed as synergistic partners enabling established and novel transformations. Systems targeted for study include palladium-based mixed ligand systems for cross-coupling reactions. Proof of concept experiments in this area have been conducted and validate the initial hypothesis of mixed ligand effects on catalyst longevity. Various architectures surrounding palladium are proposed for synthetic and catalytic investigation. Further palladium systems are proposed for investigation in hydrogenation and transfer hydrogenation of various important substrates. It should be noted that such hydrogenations mediated by palladium are rare as reduction to palladium black is often problematic. These initial experiments validate the synergistic effect proposed here for further investigation. The development of systems enabling asymmetric transformations is especially targeted. Applications in aerobic oxidation reactions are also envisaged.

配体作为过渡金属配合物的改性剂，在有机金属化学和催化中起着重要的作用。这些辅助的，通常称为旁观者，配体对催化剂活性和寿命有深远的影响。在该提议中，提出了非常具体的配体类别，即经典的P-供体（PR 3、P（OR）3、PR（OR）2、P（R2（OR））与最近采用和开发的N-杂环卡宾（NHC）的组合作为协同合作伙伴，使得能够实现建立的和新颖的转化。研究的目标系统包括用于交叉偶联反应的钯基混合配体系统。在这一领域的概念验证实验已经进行，并验证了混合配体对催化剂寿命的影响的初步假设。围绕钯的各种架构被提出用于合成和催化研究。提出了进一步的钯体系用于各种重要底物的氢化和转移氢化的研究。应该注意的是，这种由钯介导的氢化是罕见的，因为还原成钯黑通常是有问题的。这些初步实验验证了本文提出的协同效应，以供进一步研究。特别针对的是开发能够实现非对称转换的系统。还设想了在有氧氧化反应中的应用。