title: Switchable-Hydrophilicity Solvents for Product Isolation and Catalyst Recycling in Organocatalysis.
abstract: Switchable-hydrophilicity solvents (SHSs) are solvents that can switch reversibly between a water-miscible state to a state that forms a biphasic mixture with water. In this case study, SHSs have been studied for easy product/catalyst separation as well as catalyst recycling. A series of tertiary amine SHSs have been identified for the extraction of the hydrophilic product from the postreaction mixture. Here, we determined high extraction efficiencies for the product (>84%) and low extraction rates for the catalyst (<0.1%). With the catalyst recycling experiments, we isolated the product in high purity (>98%) without further purification steps. At the same time, the catalyst was reused without any loss of activity (>91% enantiomeric excess, >99% yield) four times. Furthermore, we optimized the extraction efficiency by working with a microextractor. In addition, with the use of a falling-film microreactor, we obtained the product with high enantioselectivity by working at ambient conditions.
authors.affiliation: Department of Chemistry, University of Rostock, Albert-Einstein-Str. 3a, 18059, Rostock, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Großeheilmann
authors.affiliation: Department of Chemistry, Queen's University, 90 Bader Lane, Chernoff Hall, Kingston, Ontario, K7 L 3N6, Canada.
authors.forename: Jesse R
authors.initials: JR
authors.lastname: Vanderveen
authors.affiliation: Department of Chemistry, Queen's University, 90 Bader Lane, Chernoff Hall, Kingston, Ontario, K7 L 3N6, Canada.
authors.forename: Philip G
authors.initials: PG
authors.lastname: Jessop
authors.affiliation: Department of Chemistry, University of Rostock, Albert-Einstein-Str. 3a, 18059, Rostock, Germany. udo.kragl@uni-rostock.de.
authors.forename: Udo
authors.initials: U
authors.lastname: Kragl
mesh_terms: D002384:Catalysis; D057927:Hydrophobic and Hydrophilic Interactions; D009930:Organic Chemicals / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*
chemical_list: D009930:Organic Chemicals; D012997:Solvents
keywords: catalyst recycling; downstream processing; microreactor; organocatalysis; switchable solvents