An efficient synthesis of 8-substituted Odoratine derivatives by the Suzuki coupling reaction

Rotenoids and Isoflavones from Xeroderris stuhlmannii (Taub.) Mendonça & E.P. Souza and Their Biological Activities

“…All the compounds were characterized and identified by the spectroscopic (1D and 2D NMR) and spectrometric (HRESIMS) techniques, as well as a comparison of their spectroscopic and physical data with that published in the literature. The known isolated compounds were identified as odoratin ( 6 ) [ 1 ], griffonianone D ( 7 ) [ 11 ], conrauinone A ( 8 ) [ 12 ], ichthynone ( 9 ) [ 13 , 14 ], formononetin ( 10 ) [ 15 ], 7- O -geranylformononetin ( 11 ) [ 16 ], conrauinone C ( 12 ) [ 17 ], maximaisoflavone B ( 13 ) [ 18 ], and abrusprecatin A ( 14 ) [ 19 ].…”

“…Its 1 H NMR spectrum ( Table 1 ) exhibited proton signals of flavonoids, and the signal depicted at ẟ H 7.80 (1H, s, H-2), characteristic of the proton H-2 of the isoflavonoid skeleton [ 20 ]. This spectrum further displayed a singlet for an aromatic proton at ẟ H 6.72 (1H, s, H-8), together with a singlet of a methylene dioxyl group at ẟ H 5.97 (2H, s, O-CH 2 -O) and three sharps singlets at ẟ H 3.98 (3H, s), 3.97 (3H, s), 3.75 (3H, s), a set of signals characteristic of an odoratin derivative [ 1 ]. In addition, the 1 H NMR spectrum displayed one more singlet for the methoxyl group at ẟ H 3.93 (3H, s) and two more aromatic proton singlets at ẟ H 6.63 (1H, s) and 6.85 (1H, s), assignable to two para -coupled protons of the B-ring.…”

“…Xeroderris genus belongs to the Fabaceae family, commonly known as Leguminoseae , and is an extremely rich source of biologically active compounds mainly flavonoid derivatives, which is the major class of secondary metabolites found in the family [ 1 , 2 ]. These bioactive phytochemicals possess antibacterial, antioxidant, antifungal, and antimalarial activities [ 3 , 4 , 5 ].…”

Recent advances in the synthesis of 4H-chromen-4-ones (2012 − 2021)

“…A common approach to obtain a wide variety of 3-substituted 4H-chromen-4-ones is using (E)-3-(dimethylamino)-1-(2-hydroxyaryl) prop-2-en-1-ones, commonly known as o-hydroxyaryl enaminones, as key intermediates, obtained mainly from the reaction of 2 0 -hydroxyacetophenones with DMF-DMA in DMF as solvent. Various 3-iodo-4H-chromen-4-ones arise from one-pot ring-closure and iodination sequence via addition of molecular iodine to o-hydroxyaryl enaminones employing methanol, [242][243][244][245][246][247] chloroform, 248,249 pyridine and chloroform, [250][251][252][253][254] pyridine and dichloromethane 47,255 as solvents, at room temperature. Examples of 3-fluoro-4H-chromen-4-ones were synthesized through the monofluorination of o-hydroxyaryl enaminones with Selectfluor ® as fluorine source in 1,2-DCE at room temperature, 256 in the presence of sodium acetate and butylated hydroxytoluene (BHT)…”

Greener route for the synthesis of chromone using Amberlyst®15 via enaminones

“…R. B. et.al was reported synthesis of chromone scaffolds and their 3-halogenated derivatives. [19][20] Recently, Joussot and co-workers reported an efficient synthesis of 3-substituted chromones via enamino ketones. 21 Synthesis of 3-benzylated chromones are also reported in the presence of NaI from enamino ketones and benzyl bromide.…”