Continuous flow hydrosilylation in SILP/scCO2 systems - an innovative approach to reduction andfunctionalization of alkynes, imines and carbonyl compounds

该项目的目标是设计，评估和演示具有C≡C， C=O和C=N键的分子的连续流催化硅氢化的方法。为此，将开发由分子催化剂或催化活性纳米颗粒组成的催化体系，这些催化体系稳定并固定在负载离子液相（SILP）或磷钨酸(PTA)/氧化铝（Alox）载体上。立体选择的版本也设想使用分子催化剂与手性配体。在SILP-scCO2方法中，超临界二氧化碳（scCO2）将用作流动相，将底物运输到含有SILP基质的催化剂中，同时提取产物进行分离。该方法利用了scCO2的类气体传输和类液体溶解度特性。由于有机硅化合物在压缩二氧化碳中的高溶解度和SILP材料在相同介质中的可忽略不计的溶解度，这种方法特别适合于设想的应用。在(PTA)/Alox方法的情况下，根据底物/产物的性质，将使用纯试剂、scCO2或常规溶剂来实现流动。本研究将提供有关催化与先进流体结合的基本知识，从而有助于在三个不同但紧密相连的过程水平上理解、控制和掌握连续流过程的总体进展：分子尺度：催化活性金属配合物和团簇与固定基质的分子相互作用如何影响其短期和长期性能？-中尺度：催化剂、底物和产物的物理化学性质如何与固定相和流动相相协调，总的来说，如何与整合反应和分离的设计策略协调？-宏观尺度：如何设计和建造一个紧凑的连续流装置，以实现设计的反应/分离方法，并允许反应和催化剂监测？对这三个层次的开发，重点是相互相容性，将为催化有机硅化学提供一种新的可持续方法，从而提高生产率，改善甚至是新的选择性。使用scCO2作为良性运输介质的流动化学与有效的催化剂固定程序相结合，将确保无金属和无溶剂的产品分离，从而减少任何额外的繁琐或材料密集的作业程序。我们的目标是一种灵活的方法，使各种炔和羰基化合物的连续流动硅氢化，只需进行微小的操作调整。

The goal of the project is to design, evaluate, and demonstrate methods for continuous-flow catalytic hydrosilylation of molecules bearing C≡C, C=O and C=N bonds. For this purpose, catalytic systems comprising molecular catalysts or catalytically active nanoparticles stabilized and immobilized in a supported ionic liquid phase (SILP) or on Phosphotungstic Acid (PTA)/aluminum oxide (Alox) supports will be developed. Stereoselective versions are envisaged too by using molecular catalysts with chiral ligands. In the SILP-scCO2 approach, supercritical carbon dioxide (scCO2) will be used as a mobile phase to transport substrates into the catalyst containing SILP matrix and simultaneously extract the products for isolation. This methodology takes advantagefrom the gas-like transport and liquid-like solubility properties of scCO2. Thanks to the high solubility of organosilicon compounds in compressed carbon dioxide and the negligible solubility of the SILP materials in the same medium, this approach is particularly suited for the envisaged application. In the case of the (PTA)/Alox approach, the use of neat reagents, scCO2 or conventional solvents will be used to realize the flow depending on the nature of the substrates/products. This study will provide fundamental knowledge on the combination ofcatalysis with advanced fluids, thus contributing to a general progress in the understanding,control, and mastering of continuous-flow processes at the three different, yet stronglyinterconnected, process levels:- Molecular scale: How do the molecular interactions of catalytically active metal complexes and clusters with the immobilization matrix affect their performance on the short and on the long term?- Mesoscale: How do the physico-chemical properties of the catalyst, subtrates andproducts harmonize with the stationary and mobile phase and, in general, with the devised strategy for integrating reaction and separation?- Macroscale: How should a compact continuous-flow setup be designed and constructed to implement the devised reaction/separation approach and to allow both reaction and catalyst monitoring?The exploitation of these three levels with a focus on mutual compatibility will result in a new sustainable approach for catalytic organosilicon chemistry leading to high productivities and improved or even novel selectivities. The combination of flow-chemistry using scCO2 as benign transport medium with an effective catalyst immobilization procedure will ensure metal-free and solvent-free product isolation, thus cutting down any additional tedious or material intensive workup procedures. We aim at a flexible methodology enabling the continuous flow hydrosilylation of various alkynes and carbonyl compounds with minor operational adjustments.