Author(s): Carreiro, Elisabete ; Amorim, Ana ; Fonseca, Daniela ; Burke, Anthony ; Hermann, Gesine ; Federsel, H-J
Date: 2023
Persistent ID: http://hdl.handle.net/10174/35072
Origin: Repositório Científico da Universidade de Évora
Subject(s): cinchona alkaloids; EziGTM - immobilizations; batch reactions; continuous flow reactions; organocatalysis
A well-known squaramide-cinchonine organocatalyst was immobilized in a controlled way onto three types of commercial porous glass beads EziG™ (EziG OPAL, EziG Amber, and EziG Coral) and applied in asymmetric Michael reactions. The performance of the immobilized catalysts was evaluated under batch and continuous-flow conditions, showing promising results in both approaches. In batch reactions, 0.8 and 1.6 mol% of the immobilized cinchonine-squaramide provided the products with excellent yields (up to 99%) and enantioselectivities (up to 99% ee). These excellent results were also verified in the case of continuous-flow reactions, where also 0.8 and 1.6 mol% of the catalyst immobilized onto the glass beads afforded the product with extraordinary yields (up to 99%) and very high enantioselectivities (up to 97% ee). The immobilized catalysts could be recycled (up to seven cycles) using both approaches.
