Scalable Synthesis of Acridinium Catalysts for Photoredox Deuterations

The continuous development of photocatalytic methods incentivizes the design of organic catalysts to complement the frequently used and precious polypyridyl transition metal systems. Herein, a scalable synthesis of suitable acridinium dyes and their application in photoredox deuterations are described. The acridinium catalysts, prepared on multi-gram scale, allowed the deuteration of a pharmaceutically relevant scaffold in high yield and selectivity under mild conditions.

Key words

acridinium salts - deuteration - Grignard reactions - photoredox catalysis - scalability

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References

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14 The precipitate was slowly formed after the addition of nitric acid and can be either grey or yellow (it will turn eventually yellow after drying under vacuum).
15 The Celite was washed with EtOAc.
16 The reaction mixture turns beige immediately and the color remains until the end of the reaction.
17 After heating up to 80 °C, a hot filtration allowed to remove insoluble red solids, while the precipitated product could be isolated at RT.