The development of immobilized catalysts for the preparation of deuterated organic compounds

Deuterium(D)-labelled organic compounds are used in many fields including medicinal chemistry, mechanistic studies, polymer/biological elucidation, and bioanalytical analyses. D-labelled compounds can be prepared either indirectly, via total synthetic routes (starting from deuterated substrates or by using deuterated reagents), or directly, by exchanging hydrogen (or another atom) in the target molecule with deuterium. Although both approaches can be driven using acids or bases (or reaction with D2O), the use of catalysts enables milder reaction conditions and higher functional group tolerance. However, the preparation of these catalysts [enzymes (biocatalysts), electrocatalysts, organometallic catalysts, organocatalysts, and photocatalysts] often involves expensive, lengthy, and resource-consuming procedures while many of the state-of-the-art organometallic catalysts contain rare precious metals such as iridium or palladium. Creating immobilized, recyclable versions of these catalysts represents an advance towards circular chemistry, aligning with the United Nations Sustainable Development Goals and the European Green Deal. In this application, we propose the study of three such recyclable catalysts: (1) dendrimer- and polymer-supported catalysts; (2) supramolecular catalytic gels; and (3) immobilized biocatalysts, all of which could ultimately be used in a continuous flow microreactor (CFMR) system. Currently, for the preparation of D-labelled compounds, there is only one report of an immobilized biocatalyst and no examples in the literature of (1) nor (3), despite the great advances of these materials in other areas. Our research therefore seeks to contribute to the new green economy by developing immobilized catalysts for the preparation of D-labelled organic compounds. Ultimately, we seek to demonstrate the highly coveted late stage deuteration of complex molecules such as pharmaceutical compounds using immobilized catalysts in CFMR systems.