Marie-Gabrielle Braun

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The first catalytic allylic C-H fluorination reaction using a nucleophilic fluoride source is reported. Under the influence of a Pd/Cr cocatalyst system, simple olefin substrates undergo fluorination with Et3N·3HF in good yields with high branched:linear regioselectivity. The mild conditions and broad scope make this reaction a powerful alternative to(More)
A general and efficient method for a metal-free one-pot synthesis of highly substituted fused imidazole-containing 5,5- and 5,6-fused bicyclic heterocycles is described. Starting from commercially available substrates and reagents, the reaction proceeds through two C-N bond formations and an oxidative dehydrogenation to form highly substituted products in(More)
A direct and efficient introduction of a trifluoroethylamine motif into various heteroaromatic structures, using a readily available xanthate S-[1-(N-acetylamino)-2,2,2-trifluoroethyl]-O-ethyl dithiocarbonate (5), is reported. Medicinally relevant trifluoroethylaminated heteroarenes containing a wide range of functional groups were successfully synthesized(More)
A highly demanding cross-metathesis (CM) reaction for the formation of the C24-C25 trisubstituted olefin of dolabelide C has been optimized. A difference in reactivity between the E and Z enone isomers in this reaction was uncovered, and the selection of the Z isomer of the starting enone was critical for the success of the cross-metathesis. Application to(More)
2-Fluoropyridinyl-6-oxy- precursors derived from phenyl vinyl sulfide react with radicals generated from xanthates via an addition-elimination process to furnish the corresponding vinyl sulfides in good yields. This convergent method is operationally simple and enables a straightforward synthesis of the difficult to access tetrasubstituted vinyl sulfides.(More)
Adducts from the radical addition of xanthates to ethyl vinyl sulfide readily undergo elimination of the xanthate group upon thermolysis to give vinylic and/or allylic sulfides, depending on the structure. In the case of α-xanthyl ketones, the adducts are converted into α-keto vinyl carbinols by rearrangement of the sulfoxides derived from the vinylic and(More)
A recently discovered radical fragmentation of 2-fluoro-6-pyridinoxy derivatives allows a new highly stereoselective and convergent route to (E)-vinylsulfones from allylic alcohols. Reductive desulfonylation or nickel-catalyzed couplings furnish di- and trisubstituted (E)- and (Z)-alkenes.
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