Work

A novel recyclable organocatalyst for the gram-scale enantioselective synthesis of ( S )-baclofen

Year: 2023

Type: article

Abstract: Synthesizing organocatalysts is often a long and cost-intensive process, therefore, the recovery and reuse of the catalysts are particularly important to establish sustainable organocatalytic transformations. In this work, we demonstrate the synthesis, application, and recycling of a new lipophilic cinchona squaramide organocatalyst. The synthesized lipophilic organocatalyst was applied in Michael additions. The catalyst was utilized to promote the Michael addition of cyclohexyl Meldrum’s acid to 4-chloro- trans -β-nitrostyrene (quantitative yield, up to 96% ee). Moreover, 1 mol % of the catalyst was feasible to conduct the gram-scale preparation of baclofen precursor (89% yield, 96% ee). Finally, thanks to the lipophilic character of the catalyst, it was easily recycled after the reaction by replacing the non-polar reaction solvent with a polar solvent, acetonitrile, with 91–100% efficiency, and the catalyst was reused in five reaction cycles without the loss of activity and selectivity.

Source: Beilstein Journal of Organic Chemistry

DOI: 10.3762/bjoc.19.133

Authors: Gyula Dargó, Dóra Erdélyi, Balázs Molnár, Péter Kisszékelyi, Zsófia Garádi, József Kupai

Institutions: Budapest University of Technology and Economics, Semmelweis University

Language: English

Topic: Asymmetric Synthesis and Catalysis

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

SDG: Responsible consumption and production

Open Access status: diamond

Funders: European Commission, Richter Gedeon Talentum Alapítvány, Nemzeti Kutatási, Fejlesztési és Innovaciós Alap, National Research, Development and Innovation Office