Synthesis of α,α-difluorobenzoyl oxygen heterocycles via the radical reaction of 2-iodo-2,2-difluoroacetophenones with unsaturated acids or unsaturated alcohols

A convenient and practical synthesis of β-diketones bearing linear perfluorinated alkyl groups and a 2-thienyl moiety

“…Commercial NaH is supplied in a relatively safe form of 60% dispersion in mineral oil. Although other researchers recommended to use this dispersion in native form [18–19 25], we have found that mineral oil should be removed before the synthesis. The results of the optimization experiments are summarized in Table 1.…”

“…The best results were obtained if THF solution of carbonyl compounds was slowly added dropwise to a suspension of NaH in THF, while the temperature was maintained below +5 °C. Upon completion of the condensation, the reaction mixture should be kept at room temperature for 5–10 h, because prolonged reflux, as recommended by other researchers [19,25], notably decreases the yields and purity of β-diketones.…”

“…А number of different combination of solvents, bases and reaction conditions were described in literature for this condensation. For example, t -BuOK in benzene [16], NaOMe in methanol [17], NaH in Et 2 O [18], NaH in THF [19], NaOMe in Et 2 O [20] or LiHMDS in THF [21] were tested. The yields varied from 32 to 87%.…”

Copper-Catalyzed Oxydifluoroalkylation of Hydroxyl-Containing Alkenes

“…In the past several years, oxytrifluoro­methylation and oxydifluoro­alkylation of unsaturated carboxylic acids have been reported to provide a convenient access to the corresponding trifluoromethyl-containing lactones and difluoroalkylated lactones. However, the corresponding oxyfluoroalkylation of hydroxyl-containing alkenes to afford the fluoroalkylated tetrahydrofuran has only been reported sporadically . In 2017, Liu and co-workers reported an enantioselective radical oxytrifluoro­methylation of unsaturated alcohols (Scheme , eq 1).…”