Going Soft with Iron: Sustainable Catalysis in Organoboronic Ester Chemistry

均相铁催化很有希望取代环境和经济上有害的钯催化过程，钯催化过程通常用于医药、农用化学品和许多其他工业过程的开发。铁在地壳中的丰度是钯的300多万倍，许多铁物种的毒性比钯低得多，随着化学工业努力建设更绿色的未来，铁成为一种更便宜、往往更安全的替代品。尽管铁有许多优点，但在均相催化中使用铁并不是常规的，主要是因为它的反应活性不可预测，而且在执行特定转化所需的条件下具有特异性。因此，“化学家的工具包”缺乏强大的铁催化的转化，无法复制其他金属的反应性，如钯，甚至包括镍和铜在内的其他地球上丰富的金属。其中一个目前不发达的领域是铁催化的硼化反应，特别是从sp2底物生成有机硼酸酯。这可以通过许多方法来实现，包括C-H和C-X硼化(X=卤化物、假卤化物)。该项目的第一阶段将侧重于开发一种改进的系统，用于铁催化的芳基卤化物的硼化反应，这是一个有吸引力的前景，到目前为止仅限于“活化”底物，较简单的系统表现出较低的产率。实验工作将从实验室开始，优化反应条件，进行自动化文库合成和动力学分析。计算研究将为合成工作提供支持，有助于深入了解反应机理。除了上述C-X硼化反应外，该项目还可能进展到其他铁催化的反应，包括合成有机硼物种的替代方法及其随后的应用(例如在铃木-宫浦交叉偶联反应中)。

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).