Heterogeneous ditopic ZnFe2O4catalyzed synthesis of 4H-pyrans: further conversion to 1,4-DHPs and report of functional group interconversion from amide to ester
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)]
Glycerol as a promoting medium for electrophilic activation of aldehydes: catalyst-free synthesis of di(indolyl)methanes, xanthene-1,8(2H)-diones and 1-oxo-hexahydroxanthenes
作者:Fei He、Peng Li、Yanlong Gu、Guangxing Li
DOI:10.1039/b916015a
日期:——
Glycerol was used, for the first time, as a green and effective promoting medium for electrophilic activation of aldehydes, and with which, a catalyst-free system for some reactions that conventionally carried out using acid catalysts, such as synthesis of di(indolyl)methanes, 3,4,5,6,7,9-hexahydro-9-aryl-1H-xanthene-1,8(2H)-dione and 1-oxo-hexahydroxanthenes, was developed.
CuO‐CeO2 nanocomposite is reported as a highlyefficient and recyclablecatalyst for the greensynthesis of 1,8‐dioxooctahydroxanthenes in water. This catalyst can be recovered by simple filtration and recycled up to 8 consecutive runs without any losing of its efficiency.