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Free, publicly-accessible full text available July 27, 2026
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The selective installation of fluorine-containing groups into biologically relevant molecules has been used as a common strategy for the development of pharmaceutically active molecules. However, the selective incorporation of gem-difluoromethylene groups next to sterically demanding secondary and tertiary alkyl groups remains a challenge. Herein, we report the first cobalt-catalyzed regioselective difluoroalkylation of carboxylic acid salts. The reaction allows for the facile construction of various difluoroalkylated products in good yields tolerating a wide range of functionalities on either reaction partner. The potential of the method is illustrated by the late-stage functionalization of molecules of biological relevance. Mechanistic studies support the in situ formation of a cobalt(I) species and the intermediacy of difluoroalkyl radicals, thus suggesting a Co(I)/Co(II)/Co(III) catalytic cycle.more » « less
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A photocatalytic methodology for the single step synthesis of γ-ketoacids from α-ketoacids has been developed. This method employs maleic anhydrides as traceless synthetic equivalents of acrylic acids, achieving a selective cross-coupling via a dual decarboxylative strategy, where molecular CO2 is released as the only waste byproduct. The method has also been expanded to incorporate a highly regioselective, 3-component coupling with various alcohols to access functionalized γ-ketoesters.more » « less
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Recently, dual catalytic strategies towards the decarboxylative elimination of carboxylic acids have gained attention. Our lab previously reported a photoredox/cobaloxime dual catalytic method that allows the synthesis of enamides and enecarbamates directly from N ‐acyl amino acids that avoids the use of any stoichiometric reagents. Further development, detailed herein, has improved upon this transformation’s utility and further experimentation has provided new insights into the reaction mechanism. These new developments and insights are anticipated to aid in the expansion of photoredox/cobalt dual catalytic systems.more » « less
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Abstract Since early focus on development of the allylation of non‐stabilized enolates, decarboxylative allylation has undergone tremendous evolution. This account describes the progression of decarboxylative allylation within the Tunge group with a focus on efforts to identify and overcome pKarequirements that initially limited the carboxylates that would undergo decarboxylative allylation.more » « less
