Palladium catalyzed reaction in aqueous DMF: synthesis of 3-alkynyl substituted flavones in the presence of prolinol

Catalyzed Reactions of Alkynes in Water

“…Iodobenzene was found to have good miscibility with water in the presence of prolinol and the reaction was completed within 30 min affording the desired product in a good yield. [61] Besides the phosphine ligands, nitrogen ligands are also effective. Recently, a new palladium catalyst with a nitrogen ligand, 2,2'-dipyridylmethylamine-based palladium complexes (Scheme 3), has been developed as an efficient catalyst for Sonogashira coupling in aqueous media.…”

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

“…The α-haloenones derived from α,β-unsaturated carbonyl compounds provide an important functional group that could facilitate metal-catalyzed carbon-carbon bond formation [18][19][20][21]. The 3-haloflavones (X = Br, I), for example, have been found to undergo Suzuki coupling with aromatic boronic acids to yield 2,3-diarylbenzopyran derivatives with a pharmacophore for selective cyclooxygenase-2 inhibition [21].…”

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.…”