cobalt hydrogensulfate is an efficient catalyst for the condensation of β-naphthol, aromatic aldehydes and 5,5-dimethyl-1,3-cyclohexanedione at 120 °c to afford 9,9-dimethyl-12-phenyl-8,10,11,12-tetrahydro-9-h-benzo[a]xanthen-11-one derivatives in high yields. also, polycondensation reactions of phenols with phthalic anhydride were carried out in the presence of cobalt hydrogensulphate under so...

Following the results we previously reported on a series of xanthene and xanthone derivatives as G-quadruplex stabilizing ligands, in order to obtain a more selective compound with respect to the previous generation of derivatives, we decided to modify the structure of the core ligand, specifically its aromatic extension. In particular, here we report the design, synthesis and activity data of ...

Enoate reductases from the family of old yellow enzymes (OYEs) can catalyze stereoselective trans-hydrogenation of activated C=C bonds. Their application is limited by the necessity for a continuous supply of redox equivalents such as nicotinamide cofactors [NAD(P)H]. Visible light-driven activation of OYEs through NAD(P)H-free, direct transfer of photoexcited electrons from xanthene dyes to th...

In order to study the structure-activity relationships of xanthene derivatives, four series of N-substituted 14-aryl-14H-dibenzo[a,j]xanthene-3,11-dicarboxamide derivatives were synthesized. The structures of all compounds were identified by ¹H-NMR, HR-MS and IR spectra, in which compounds 6a-h were further identified by 13C-NMR spectra. The in vitro antitumor activity of the synthesized compou...

cobalt hydrogensulfate is an efficient catalyst for the condensation of β-naphthol, aromatic aldehydes and 5,5-dimethyl-1,3-cyclohexanedione at 120 °c to afford 9,9-dimethyl-12-phenyl-8,10,11,12-tetrahydro-9-h-benzo[a]xanthen-11-one derivatives in high yields. also, polycondensation reactions of phenols with phthalic anhydride were carried out in the presence of cobalt hydrogensulphate under so...

Benzo[kl]xanthene lignans, promising bioactive polyphenols obtained by biomimetic oxidative coupling of caffeic acid derivatives, react efficiently with peroxyl radicals in both polar and non-polar solvents, thanks to the simultaneous presence of guaiacol-like and catechol-like OH-groups.

a green and convenient méthode for the synthesis of  a variety of xanthene derivatives by condensation reaction between aldehydes and β-naphthol or dimedone in an micellar solution of sodium dodecylphosphonate is described. this method offers several advantages, such as using of a cheap and environmentally benign reaction media, low loadings of sodium dodecylphosphonate as catalyst and easy wor...

In the title compound, C(27)H(26)O(4), each of the cyclo-hexenone rings adopts a half-chair conformation. The dihedral angle between the two phenyl rings is 89.53 (5)°. The hy-droxy and carbonyl O atoms face each other and are orientated to allow the formation of two intra-molecular O-H⋯O hydrogen bonds, which are typical of xanthene derivatives.