Abstract

Gas-liquid Photochemical Reactions in Flow

Timothy Noël, Professor, University of Amsterdam

Photoredox catalysis is emerging as a new and powerful tool in synthetic organic chemistry to facilitate such photochemical reactions by means of visible light. Notable examples involve the use of ruthenium(II)polypyridine complexes which upon irradiation produce a photoexcited state. This photoexcited state gives rise to a single electron transfer process (SET) with organic substrates which can undergo subsequently a synthetic transformation. Whereas a myriad of different reactions have recently succumbed to this mode of catalysis, it is important to note that several challenges still remain with respect to high catalyst loadings, extended reaction times, scalability, quantum yield and generality of the catalyst system. In this oral communication, we will report on the acceleration of gas-liquid photocatalytic reactions in continuous photomicroreactors. We will go into detail on both engineering and chemical/catalytic aspects of continuous-flow photochemistry. Relevant examples from our group, such as the photocatalytic aerobic disulfide formation will be detailed on during the presentation. Furthermore, we will discuss the engineering aspects concerned with photocatalytic gas liquid reaction in flow. This includes the potential (i) to extract efficiently kinetics,(ii) to increase the energy efficiency of the photomicroreactor and (iii) to scale-up the chemistry with a numbering-up strategy. Insight information will be provided about the discovery process and the different parameters that led to success.