title: Accelerated gas-liquid visible light photoredox catalysis with continuous-flow photochemical microreactors.
abstract: In this protocol, we describe the construction and use of an operationally simple photochemical microreactor for gas-liquid photoredox catalysis using visible light. The general procedure includes details on how to set up the microreactor appropriately with inlets for gaseous reagents and organic starting materials, and it includes examples of how to use it to achieve continuous-flow preparation of disulfides or trifluoromethylated heterocycles and thiols. The reported photomicroreactors are modular, inexpensive and can be prepared rapidly from commercially available parts within 1 h even by nonspecialists. Interestingly, typical reaction times of gas-liquid visible light photocatalytic reactions performed in microflow are lower (in the minute range) than comparable reactions performed as a batch process (in the hour range). This can be attributed to the improved irradiation efficiency of the reaction mixture and the enhanced gas-liquid mass transfer in the segmented gas-liquid flow regime.
authors.affiliation: Eindhoven University of Technology, Department of Chemical Engineering and Chemistry, Micro Flow Chemistry and Process Technology, Eindhoven, the Netherlands.
authors.forename: Natan J W
authors.initials: NJ
authors.lastname: Straathof
authors.affiliation: Eindhoven University of Technology, Department of Chemical Engineering and Chemistry, Micro Flow Chemistry and Process Technology, Eindhoven, the Netherlands.
authors.forename: Yuanhai
authors.initials: Y
authors.lastname: Su
authors.affiliation: Eindhoven University of Technology, Department of Chemical Engineering and Chemistry, Micro Flow Chemistry and Process Technology, Eindhoven, the Netherlands.
authors.forename: Volker
authors.initials: V
authors.lastname: Hessel
authors.affiliation: Eindhoven University of Technology, Department of Chemical Engineering and Chemistry, Micro Flow Chemistry and Process Technology, Eindhoven, the Netherlands.|Department of Organic Chemistry, Ghent University, Ghent, Belgium.
authors.forename: Timothy
authors.initials: T
authors.lastname: Noël
mesh_terms: D002384:Catalysis; D005740:Gases / Q000737:chemistry*; D007700:Kinetics; D056656:Lab-On-A-Chip Devices; D008027:Light; D009930:Organic Chemicals / Q000737:chemistry; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D010777:Photochemistry / Q000295:instrumentation*
chemical_list: D005740:Gases; D009930:Organic Chemicals; D010100:Oxygen