Operando Analysis of Industrially Relevant Rh-P catalysed Olefin Hydroformylation by Multi-Nuclear FlowNMR Spectroscopy

在这个项目中，我们将使用operando FlowNMR作为工具，以获得前所未有的深入了解由铑-膦络合物介导的氢甲酰化催化。尽管烯烃氢甲酰化是一项成熟的技术，并且是世界上最大的均相催化过程之一，但围绕化学、区域和对映体选择性的起源，以及导致该化学反应中不需要的副产物形成的休眠和失活催化剂物种，仍然存在许多与应用相关的问题。对于一些更“不寻常”的膦来说尤其如此，例如赢创的大体积膦酸盐和双膦酸盐，以及伊士曼的氟膦酸盐，它们在令人惊讶的温和条件下具有高水平的n选择性。了解它们与经典芳基膦威尔金森体系不同的方式和原因，有助于获得设计原则，从而开发出适合所需产品选择性的改进系统，从而形成新的、更清洁、更有效的氢甲酰化过程的基础。我们将利用巴斯在操作型FlowNMR光谱方面的独特能力，通过快速定量的原位1H， 19F和31P FlowNMR来跟踪催化剂的活化，周转，回收和再利用。多维相关光谱、选择性解耦、异核扩散分析和极化转移实验，结合低强度信号的选择性激发，将全面了解可能与整个反应过程直接相关的催化剂形态形成。一个特别的重点将是确定进入休眠物种的途径，不可逆的失活和不必要的副产物形成，这些都是大规模应用的重要考虑因素。谱迹将通过反应过程动力学分析（RPKA）使用可变时间归一化（VTN）进行分析，以建立描述催化体系行为的所有相关参数的固体动力学描述符。

In this project we will use operando FlowNMR as a tool to gain unprecedented levels of insight into hydroformylation catalysis mediated by rhodium-phosphine complexes. Although olefin hydroformylation is a well-established technology and with >10 Mt p.a. one of the largest homogeneously catalysed processes in the world, there still are many application-relevant questions around the origin of chemo-, regio- and enantioselectivity as well as dormant and deactivated catalyst species leading to the formation of unwanted side-products in this chemistry. This is particularly true for some of the more 'unusual' phosphines such as Evonik's bulky phosphonites and bis-phosphites and as well as Eastman's fluoro-phosphites that give high levels n-selectivity under surprisingly mild conditions. Understanding how and why they differ from the classical aryl-phosphine Wilkinson systems promises access to design principles that will allow the development of improved systems that be tailored to a desired product selectivity, and thus form the basis of new, cleaner and more efficient hydroformylation processes.We will use Bath's unique capabilities in operando FlowNMR spectroscopy to follow catalyst activation, turnover, and recovery & reuse by rapid and quantitative in-situ 1H, 19F and 31P FlowNMR. Multi-dimensional correlation spectroscopy, selective decoupling, hetero-nuclear diffusion analysis and polarisation transfer experiments in conjunction with selective excitation of low intensity signals will give a comprehensive picture of catalyst speciation that may be directly correlated with the overall reaction progress. A particular focus will lie on identifying pathways that lead into dormant species, irreversible deactivation and unwanted side-product formation, all important considerations for large-scale application. Spectral traces will be analysed by Reaction Progress Kinetic Analysis (RPKA) using Variable Time-Normalization (VTN) to establish solid kinetic descriptors for all relevant parameters describing the behaviour of the catalytic system.