Going Soft with Iron: Sustainable Catalysis in Organoboronic Ester Chemistry

均相铁催化具有很大的前景，以取代环境和经济上有害的钯催化过程，这是常规用于开发药物，农用化学品和许多其他工业过程。铁在地壳中的含量是钯的300万倍以上，许多铁物种的毒性比钯的毒性低得多，随着化学工业努力实现更绿色的未来，铁成为一种更便宜、更安全的替代品。尽管铁有许多优点，但在均相催化中使用铁并不常见，这主要是由于它的不可预测的反应性和进行特定转化所需条件的特异性。因此，“化学家的工具包”缺乏强大的铁催化转化，可以复制其他金属中的反应性，例如钯，甚至包括镍和铜在内的其他地球丰富的金属。一个这样的领域，目前是欠发达的是铁催化的硼化，特别是从sp2底物的有机硼酸酯的生成。这可以通过许多方法实现，包括C-H和C-X硼基化（X =卤化物、拟卤化物）。该项目的初始阶段将侧重于开发一种用于芳基卤化物的铁催化硼基化的改进系统，这是一个有吸引力的前景，迄今为止仅限于“活化”底物，较简单系统的产率较低。实验工作将在实验室中开始，优化反应条件，进行自动化文库合成和动力学分析。支持合成工作，计算研究将提供深入了解反应机理。除了上述C-X硼基化反应，该项目可能会发展到其他铁催化反应，包括合成有机硼物种的替代方法及其后续应用（例如Suzuki-Miyaura交叉偶联）。

Homogeneous iron catalysis holds a great deal of promise to replace environmentally and economically deleterious palladium-catalysed processes, which are routinely used in the development of pharmaceuticals, agrochemicals and numerous other industrial processes. Iron is over 3,000,000 times more abundant in the Earth's crust than palladium, and many iron species have much lower toxicity than their palladium counterparts, presenting iron as a cheaper and often safer alternative as the chemical industry strives towards a greener future. Despite its numerous advantages, the use of iron in homogeneous catalysis is not routine, owing largely to it's unpredictable reactivity and the specificity in conditions required to perform a particular transformation. As a result, the 'chemist's toolkit' is lacking in robust iron-catalysed transformations that can replicate reactivity seen in other metals, such as palladium and even other Earth-abundant metals including nickel and copper. One such area that is currently underdeveloped is iron-catalysed borylation, particularly the generation of organoboronic esters from sp2 substrates. This can be achieved through numerous methods, including C-H and C-X borylation (X = halide, pseudohalide). The initial phase of the project will focus on the development of an improved system for iron-catalysed borylation of aryl halides, an attractive prospect which has thus far been limited to 'activated' substrates only, with poor yields demonstrated for simpler systems. The experimental work will begin in the laboratory with optimisation of the reaction conditions, progressing to automated library synthesis and kinetic analysis. Supporting the synthetic work, computational investigations will provide insight into reaction mechanism. Beyond the aforementioned C-X borylation reaction, the project is likely to progress to other iron-catalysed reactions, including alternative methods for the synthesis of organoboron species and their subsequent application (e.g. in Suzuki-Miyaura cross-couplings).