A palladium-catalyzed (Pd(PPh3)4/Ag2O/PivOH) C2-regioselective direct dehydrogenative alkynylation of unsubstituted selenophene was achieved. The selenophenes substituted with R1 groups at 2-position can be C5-alkynylated with a variety of 4-substituted phenylacetylenes (R2 groups). The R1 and R2 can be either electron-withdrawing or electron-donating groups, demonstrating a wide range of substrate
This invention relates to selenophene compounds of formula (I) shown below. Each variable in formula (I) is defined in the specification. These compounds can be used to treat cannabinoid-receptor mediated disorders.
Investigations of simple formoins such as 2,5-bis(1,1-dimethyl-2-phenylethyl)-2,4-dihydroxyfuran-3(2H)-one (17), benzoylformoin (18), p-toluoylformoin (19), pivaloylformoin (20), and the 2,4-dihydroxy-2,5-bis(heterocycl-2-yl)furan-3-ones 21−23 (heterocycle = furan, thiophene, selenophene) by NMR spectroscopy in DMSO showed the dihydroxyfuranone skeleton and not an enediol structure. The formoin 17 was oxidized
Hetaryl-substituted thiochalcones react with acetylenic mono- and diesters in the THF solution in the presence of LiClO4 at 65°C to give, after 24 h, 4H-thiopyran carboxylates and dicarboxylates, respectively, in moderate to good yields. The same reactions were performed also in the THF solution without a catalyst under microwave irradiation. In that case, the reaction time was reduced to three minutes and
Selenoyl-trifluoroacetone: Synthesis, properties, and complexation ability towards trivalent rare-earth ions
作者:Maxim A. Lutoshkin、Ilya V. Taydakov
DOI:10.1016/j.poly.2021.115383
日期:2021.10
using NMR, EI-MS, and elemental analysis. Spectral, acid-base, complexing, and keto-enol parameters were studied under various conditions. Received values of dissociation and protonation constants characterize selenoyltrifluroracetone as a stronger acid and stronger base than acetylacetone. The aqueous chelation with sixteen rare-earthmetals has been studied in acetate and glycine buffer media at I = 0