This study presents an improved synthetic route to ligand (S)-4-(tert-butyl)-2-(5-(trifluoromethyl)pyridin-2-yl)-4,5-dihydrooxazole and its application as a highly active and enantioselective catalyst in the addition of arylboronic acids to cyclic N-sulfonylketimines. Immobilization of such a ligand was achieved using a commercially available starting material and a PS-PEG TentaGel S NH2 support, resulting in a stable heterogeneous catalyst. Although the anchored catalyst exhibited a slight reduction in enantioselectivity and a 4-fold decrease in reaction rate, it displayed remarkable stability, enabling 10 consecutive reaction cycles. Furthermore, the successful transition to a continuous flow system demonstrated even higher turnover numbers compared to batch arrangements. These findings provide valuable insights into the development of efficient flow reactors for continuous synthesis of benzosultams, further advancing the field of asymmetric catalysis.

Biomedical Research Center University Hospital Hradec Králové Sokolská 581 Hradec Králové CZ 500 05 Czech Republic

Department of Analytical Chemistry Faculty of Chemical Technology University of Pardubice Studentská 573 Pardubice CZ 532 10 Czech Republic

Faculty of Military Health Sciences University of Defence Trebešská 1575 Hradec Králové CZ 500 01 Czech Republic

Faculty of Pharmacy in Hradec Králové Charles University Akademika Heyrovského 1203 50005 Hradec Králové CZ 500 05 Czech Republic

Institute of Organic Chemistry and Technology Faculty of Chemical Technology University of Pardubice Studentská 573 Pardubice CZ 532 10 Czech Republic

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