Rate enhancement of lipase-catalyzed reaction using CO2-expanded liquids as solvents for chiral tetralol synthesis. (8th June 2022)

• Record Type: Journal Article
• Authors: Suzuki, Yuichi; Taniguchi, Kosuke; Hoang, Hai Nam; Tamura, Mayumi; Matsuda, Tomoko
• Is Part Of: Tetrahedron letters. Volume 99(2022)
• Publication Date: 2022-06-08
• Subjects: CO2-expanded liquid -- Bio-based liquid -- 1-Tetralol -- 2-Tetralol -- Lipase -- Chiral compound; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tetlet.2022.153837
• Languages: English
• ISSNs: 0040-4039

Abstract

Graphical abstract: Highlight: The investigation of the applicability of CO2 as a solvent is important. The CO2 -expanded liquids as solvents for a lipase-catalyzed reaction were examined. CO2 -expanded MeTHF accelerated the reaction rate by up to 40 times that without CO2 . Chiral tetralols, important drug intermediates, were synthesized ( ee up to > 99%). Abstract: The investigation on the applicability of CO2 as a solvent has been increasingly important due to the need to develop efficient reactions replacing ordinary organic solvents derived from fossil fuel with sustainable solvents such as pressurized CO2 . In our previous study of solvent engineering of a lipase-catalyzed reaction of bulky substrates, the conversions were higher for the reaction in CO2 -expanded liquids, liquids expanded by dissolving pressurized CO2, than that in the liquids without CO2 . This study demonstrates the detailed examination of CO2 -expanded liquids as solvents for lipase-catalyzed kinetic resolution of racemic 1-tetralol, 2-tetralol, and substituted 1-tetralol analogs since chiral substituted tetralol analogs are important pharmaceutical intermediates. CO2 -expanded liquids accelerated the reaction rate by up to 40 times of the reactions without CO2 while maintaining excellent enantioselectivities ( E > 200). Preparative scale reactions of racemic 1-tetralol and 2-tetralol successfully gave the corresponding ( R )-acetates and ( S )-alcohols with high yields and excellent enantioselectivities (up to ee > 99%).