Synthesis of 3-Iodo Derivatives of Flavones, Thioflavones and Thiochromones

Synthesis and further studies of chemical transformation of the 2-aryl-3-halogenoquinolin-4(1H)-one derivatives

“…So far very limited methods have been reported for the C-3 iodination of flavone analogues [14,15]. Iodine-cerium(IV) ammonium nitrate [14] and bis(pyridine)iodonium(I) tetrafluoroborate (IPy 2 BF 4 ) in dichloromethane [15] were employed previously for the C-3 iodination of thioflavone analogues.…”

“…Iodine-cerium(IV) ammonium nitrate [14] and bis(pyridine)iodonium(I) tetrafluoroborate (IPy 2 BF 4 ) in dichloromethane [15] were employed previously for the C-3 iodination of thioflavone analogues. We required a simple method that employs readily available and easy-to-handle reagents for the iodination of substrates 1.…”

Synthesis of paramagnetic and diamagnetic flavones and flavanones

“…The latter was oxidized to the 1,3-diketone 22 by MnO 2 in CHCl 3 . Sonogashira reaction of 3-iodo-4'-methoxyflavone 23 20 with the paramagnetic acetylene compound 24, 21 in the presence of L-prolinol, CuI and a palladium catalyst, gave a flavone derivative 25 22 where attachment to the pyrroline ring was from the 3 position of the C ring via an ethynyl spacer ( Figure 3). In conclusion, classical synthetic methodologies could be used for the synthesis of paramagnetic flavone and flavanone derivatives containing nitroxides on the B and C rings.…”

Photo-induced tandem cyclization of 3-iodoflavones with electron rich five-membered heteroarenes

“…General procedure for the preparation of 3-iodoavones 1 28 A solution of 2-(4-methoxyphenyl)-4H-chromen-4-one (1.0 mmol), I 2 (1.2 mmol) and CAN (1.1 mmol) in anhydrous MeCN (100 mL) was stirred at 65 C (oil/water bath) under an Ar atmosphere until the disappearance of the substrate. Aer being cooled to ambient temperature, the reaction mixture was poured into a cold solution of Na 2 S 2 O 3 (50 mL, 0.1 M) and extracted with CH 2 Cl 2 (20 mL, Â3).…”