Gaining Selectivity Control in Homogeneous Catalytic Ester Formation and Reduction with Multi-Nuclear High Resolution FlowNMR Spectroscopy

这项研究最初打算考察Gusev的NNP催化剂以及氢气将苯甲酸甲酯还原为苯甲醇。为了确定催化循环和动力学，正在利用动态反应监测技术；特别是流动核磁共振，它具有实时发现均相溶液化学性质的详细和定量变化的独特能力，从而使用户能够识别中间物种。有了这些信息，人们就可以设计出理想的条件和/或催化剂，以避免抑制效应或催化剂失活。目前存在许多与进一步了解这些钳形催化剂的机理有关的问题，包括：水分的影响似乎不利于反应，乙酯作为底物相对于其他底物的明显优势，或者被认为与催化剂失活有关的不饱和底物的异构化。Flow核磁共振的使用提供了一个强大的工具，可以用它来回答这些问题和其他问题。我将在进行实时核磁共振测量的同时设置加氢反应，以便计算和分析反应的化学成分。该项目的目标如下：-展示用于酯加氢的Ru钳形催化剂的高活性；保证更换传统的化学计量氢化物试剂，从而带来环境和经济效益。-通过使用动态反应监测/1H和31P流动核磁共振光谱进行详细分析，研究酯加氢和转移氢化的催化机理。-确定催化剂失活的途径和原因。-利用获得的反应动力学知识优化未来的反应条件和催化剂。

This research initially intends to look at Gusev's NNP catalyst and the reduction of methyl benzoate to benzyl alcohol with H2. In order to determine the catalytic cycle and kinetics, dynamic reaction monitoring techniques are being utilised; particularly FlowNMR which has the unique ability to find detailed and quantitative changes in the chemical nature of a homogeneous solution in real time and thus give the user the capability to identify intermediate species. With such information, one could design ideal conditions and/or catalysts to avoid inhibitive effects or catalyst deactivation.Already many questions exist relating to further understanding the mechanism of these pincer catalysts including: the effect of moisture which appears to be detrimental to the reaction, the apparent superiority of ethyl esters as substrates compared to others or the isomerisation of unsaturated substrates thought to be linked to catalyst deactivation. The use of FlowNMR presents a powerful tool with which these questions and others can be answered. I will be setting up hydrogenation reactions while taking live NMR measurements to allow me to calculate and analyse the chemistry of the reaction.The aims of the project are as follows:- Demonstrate high activity with Ruthenium pincer catalysts for ester hydrogenation; warranting replacement of traditional stoichiometric hydride reagents and thus bringing environmental and economic benefits.- Investigate catalytic mechanism for ester hydrogenation and transfer hydrogenation with detailed analysis using dynamic reaction monitoring / 1H and 31P FlowNMR spectroscopy.- Identify pathway and causes for catalyst deactivation.- Use acquired knowledge of reaction kinetics to optimise future reaction conditions and catalysts.