Synthesis of a library of SCF2CO2Et reagents: An access to original (ethoxycarbonyl)difluoromethylthioesters

Distal Construction of a Carbon‐SCF2R Bond on Aliphatic Alcohols Enabled by 1,5‐Hydrogen‐Atom Transfer

“…or 2,2,6,6-tetramethylpiperidine-Noxyl (TEMPO, 2-4 equiv. ), no product was observed by 19 F NMR. [21] These results suggested that a free radical pathway might be involved and reinforced our working hypothesis shown in Scheme 1, B.…”

“…Variation from standard reaction conditions Yield (%) [a] 1 None (51) No light NR [a] Yields were determined by 19 F NMR spectroscopy using the α,α,α-trifluoroacetophenone as an internal standard. [b] Isolated yields were given in parentheses.…”

“…In order to get more information about the transformation, radical trapping experiments were conducted. When the reaction was carried out in the No light NR [a] Yields were determined by 19 F NMR spectroscopy using the α,α,α-trifluoroacetophenone as an internal standard. F NMR spectroscopy of the crude reaction mixture.…”

“…Interestingly, the incorporation of the SCF 3 moiety on alcohols substituted with a cyclohexyl or an adamantyl group at the γ-position was possible leading to the corresponding products 4 in 44% yield as a mixture of diastereoisomers (dr = 1.2/1) and 5 in 42% yield, respectively. The function- 19 F NMR spectroscopy of the crude reaction mixture. [a] The product contains an inseparable impurity.…”

“…Any changes from these reaction conditions such as the nature of the solvent (Table 1, entries 2-4) and the concentration (Table 1, entry 5) led to a significant drop of the reaction efficiency. Replacement of the hypervalent iodine source from PIDA to PIFA afforded the expected product in only 35% 19 F NMR yield (Table 1, entry 6). A control experiment was conducted in the absence of light irradiation, leading to a total shutdown of the reactivity (Table 1, entry 7).…”