Enabling and Accelerating Metallocatalysis with Hydrogen Bonding

利用氢键实现并加速金属催化

• 批准号: EP/F000316/1
• 负责人: Jianliang Xiao
• 金额: $ 42.82万
• 依托单位: University of Liverpool
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2007
• 资助国家: 英国
• 起止时间: 2007 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FF000316%2F1
• 关键词: Enabling; Accelerating; Metallocatalysis; Hydrogen; Bonding

There are numerous important catalytic reactions that require the dissociation/displacement of a hydrogen bonding anion, e.g. halide and acetate anions, or a functional group, such as amines or carbonyls, from the catalytic centre. In many such reactions, the dissociation/displacement process impacts on the reaction rates and selectivities. Indeed, the presence of such a functionality coordinated to the catalyst can inhibit the catalysis entirely. We have recently discovered that the addition of simple, readily accessible hydrogen bond donors (HBD) can dramatically accelerate palladium-catalysed reactions such as the internal arylation of olefins by aryl bromides. The reaction rates we observed equal or exceed all previous catalytic systems for these reactions. We believe that the HBD functions by complexing the halide anion, aiding its removal from the metal coordination sphere without the need for, e.g., stoichiometric, toxic thallium salts as additives. It has recently been stated that The capacity to control anion-cation interactions is key to optimizing yield, chemoselectivity, regioselectivity, and stereoselectivity of chemical processes .... (Chem. Rev. 2005, 105, 2039). In this project, we wish to demonstrate that we can use hydrogen bonding to do this. In particular we will show that we can apply HBDs in order to: (i) accelerate, and direct, metallocatalysis; (ii) enable cascade metallo-organo catalytic reactions; and thus (iii) show that HBDs afford a new means of controlling catalytic activity and selectivity, and should always be considered for reactions in which hydrogen bonding anions/functionalities are involved. The capability to integrate homogeneous catalysis with organocatalysis to enable cascade metallo-organo catalysis would open up an exciting new area of catalysis, metallo-organo catalysis, given the promise being demonstrated by the emerging organocatalysis.

有许多重要的催化反应需要氢键阴离子的解离/位移，例如来自催化中心的卤化物和乙酸盐阴离子或功能组，例如胺或羰基。在许多这样的反应中，解离/位移过程会影响反应率和选择性。实际上，与催化剂协调的这种功能的存在可以完全抑制催化。我们最近发现，添加简单的，易于获得的氢键供体（HBD）可以显着加速钯催化反应，例如通过芳基溴化物的烯基芳基化的内芳基化。对于这些反应，我们观察到的反应速率相等或超过了所有先前的催化系统。我们认为，HBD通过将卤化物阴离子复合，可帮助其从金属配位球体中移除，而无需（例如化学计量，有毒的硫盐盐）作为添加剂。最近已经指出，控制阴离子相互作用的能力是化学过程的优化产量，化学选择性，区域选择性和立体选择性的关键。在这个项目中，我们希望证明我们可以使用氢键来做到这一点。特别是我们将证明我们可以应用HBD以：（i）加速和直接的金属催化； （ii）启用级联金属货号催化反应；因此（iii）表明，HBD提供了控制催化活性和选择性的新方法，应始终考虑涉及氢键阴离子/功能的反应。鉴于新兴的有机刻分析证明了这一承诺，将均相催化与有机刻分析相结合以实现级联金属 - 轨道催化的能力将开辟一个令人兴奋的新的催化区域，金属货物 - 货号催化。

项目成果

Feeding the Heck Reaction with Alcohol: One-Pot Synthesis of Stilbenes from Aryl Alcohols and Bromides

• DOI: 10.1002/adsc.201200340
• 发表时间: 2012-05-01
• 期刊: ADVANCED SYNTHESIS & CATALYSIS
• 影响因子: 5.4
• 作者: Colbon, Paul;Barnard, Jonathan H.;Xiao, Jianliang
• 通讯作者: Xiao, Jianliang

Effect of hydrogen bonding on ligand substitution and its implication for the Heck reaction

氢键对配体取代的影响及其对 Heck 反应的影响

• DOI: 10.1016/j.jorganchem.2018.11.010
• 发表时间: 2019
• 期刊: Journal of Organometallic Chemistry
• 影响因子: 2.3
• 作者: Ruan J

Double arylation of allyl alcohol via a one-pot Heck arylation-isomerization-acylation cascade.

• DOI: 10.1021/ol202144z
• 发表时间: 2011-09
• 期刊: Organic letters
• 影响因子: 5.2
• 作者: P. Colbon;J. Ruan;M. Purdie;K. Mulholland;Jianliang Xiao