Waste-minimized continuous flow copper-catalyzed azide-alkyne cycloaddition with low metal contamination

Metal contamination is a waste-generating and serious issue in the synthesis of chemicals, in particular in the case of products with biological activity. The appropriate selection of operating conditions plays a crucial role in the abatement of metal leaching in solution and associated wastes. Here...

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Bibliographic Details
Main Authors: Giulia Brufani, Federica Valentini, Gabriele Rossini, Lucia Rosignoli, Yanlong Gu, Ping Liu, Luigi Vaccaro
Format: Article
Language:English
Published: KeAi Communications Co. Ltd. 2023-05-01
Series:Green Synthesis and Catalysis
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Online Access:http://www.sciencedirect.com/science/article/pii/S2666554923000042
Description
Summary:Metal contamination is a waste-generating and serious issue in the synthesis of chemicals, in particular in the case of products with biological activity. The appropriate selection of operating conditions plays a crucial role in the abatement of metal leaching in solution and associated wastes. Herein we report a waste-minimized continuous flow process for the synthesis of 1,4-disubstituted β-keto 1,2,3-triazoles exploiting the use of a copper tube flow reactor (CTFR). The selection of the proper azeotropic mixture allowed an almost quantitative recovery of the reaction medium greatly influencing the E-factor of the protocol. A thorough understanding of the main parameters affecting the waste generation was given by calculation of the E-factor distribution for different work-up tested under batch and flow conditions. Furthermore, the measurement of different green metrics (AE: Atom Economy, SF: Stoichiometric Factor, RME: Reaction Mass Efficiency, and MRP: Mass Recover Parameter) clearly demonstrated the benefits of the flow scale-up that allowed to perform a low environmental footprint CuAAC reaction.
ISSN:2666-5549