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Radical Trifluoroacetylation of Alkenes Triggered by a Visible‐Light‐Promoted C–O Bond Fragmentation of Trifluoroacetic Anhydride
Author(s) -
Zhang Kun,
Rombach David,
Nötel Nicolas Yannick,
Jeschke Gunnar,
Katayev Dmitry
Publication year - 2021
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202109235
Subject(s) - trifluoroacetic anhydride , chemistry , trifluoromethylation , regioselectivity , photochemistry , reagent , fragmentation (computing) , bond cleavage , molecule , combinatorial chemistry , organic chemistry , catalysis , trifluoromethyl , alkyl , computer science , operating system
Abstract We report a mild and operationally simple trifluoroacylation strategy of olefines, that utilizes trifluoroacetic anhydride as a low‐cost and readily available reagent. This light‐mediated process is fundamentally different from conventional methodologies and occurs through a trifluoroacyl radical mechanism promoted by a photocatalyst, which triggers a C−O bond fragmentation. Mechanistic studies (kinetic isotope effects, spectroelectrochemistry, optical spectroscopy, theoretical investigations) highlight the evidence of a fleeting CF 3 CO radical under photoredox conditions. The trifluoroacyl radical can be stabilized under CO atmosphere, delivering the trifluoroacetylation product with higher chemical efficiency. Furthermore, the method can be turned into a trifluoromethylation protocol by simply changing the reaction parameters. Beyond simple alkenes, this method allows for chemo‐ and regioselective functionalization of small‐molecule drugs and common pharmacophores.