simple, efficient, and environmentally benign route was developed for the preparation of 14-aryl or alkyl-14H-dibenzo[a,j]xanthene, 1,8-dioxo-octahydroxanthene and 12-aryl—8,9,10,12-tetrahydrobenzo[a]xanthene-11-ones from condensation of various aldehydes with (i) β-naphthol, (ii) cyclic 1,3-dicarbonyl compounds and (iii) β-naphthol and cyclic 1,3-dicarbonyl compounds, using novel polymeric catalyst [poly(AMPS-co-AA)]
O-Sulfonated poly(4-vinylpyrrolidonium) chloride is prepared from the reaction of poly(4-vinylpyrrolidone) [PVP], as a cheap and commercially available reagent, and neat chlorosulfonic acid at room temperature. A variety of techniques including infrared spectra (IR), thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), X-ray diffraction (XRD), pH analysis and Hammett acidity (Ho) were used to characterize this solid acid. This polymeric reagent showed excellent catalytic activity for the synthesis of xanthene derivatives including 1,8-dioxooctahydroxanthenes, 14-aryl-14H-dibenzo[a,j] xanthenes and 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthen-11-ones under solvent free conditions. The products were formed in excellent yields over short reaction times and the catalyst can be reused several times without any appreciable loss in its activity.
Sulfonation of carbonized xylan-type hemicellulose: a renewable and effective biomass-based biocatalyst for the synthesis of O- and N-heterocycles
作者:Jiliang Ma、Xinwen Peng、Linxin Zhong、Runcang Sun
DOI:10.1039/c8nj01329b
日期:——
application of biomass-based carbonaceous solidacids in catalysis is attracting increasing attention in the field of chemistry. In this study, a heterogeneous carbon-based solidacid biocatalyst (CXH-SO3H) with regular spherical structure was synthesized from xylan-type hemicellulose (XH) by a simple two-step method. The catalyst was successfully applied in the synthesis of O- and N-heterocycles with yields
Résumé Cerium(III) chloride is found to be an highly efficient catalyst for the addition of aldehydes, β-naphthol and cyclic 1,3-dicarbonyl compounds/Meldrum's acid via a multicomponent reaction. The easy availability of starting materials, novel and eco-friendly procedure makes this strategy more useful for the preparation of tetrahydrobenzo[a]-xanthen-11-one, and benzo[f]chromen-3-one derivatives.
A magnetic nanoparticle supported dual acidic ionic liquid: a “quasi-homogeneous” catalyst for the one-pot synthesis of benzoxanthenes
作者:Qiang Zhang、Hong Su、Jun Luo、Yunyang Wei
DOI:10.1039/c1gc16031a
日期:——
A novel magneticnanoparticle supported dual acidic ionic liquid catalyst was synthesized by anchoring 3-sulfobutyl-1-(3-propyltriethoxysilane) imidazolium hydrogen sulfate onto the surface of silica-coated Fe3O4 nanoparticles. Due to the combination of nano-support features and flexible imidazolium linkers, it acted as a “quasi-homogeneous” catalyst to effectively catalyze the one-pot synthesis of