A novel antibacterial substance, AB0022A, was isolated from the cellular slime mold Dictyostelium purpureum K1001. It inhibited the growth of Gram-positive bacteria, and its MICs ranged from 0.39 to 50 μg/ml. Because AB0022A was a highly substituted aromatic compound, we could not determine its structure based on only its physico-chemical and spectral data. We therefore used a dehalogenated derivative from AB0022A and deduced that its structure was l, 9-dihydroxy-3, 7-dimethoxy-2-hexanoyl-4, 6, 8-trichlorodibenzofuran. To confirm this structure, we synthesized the compound having the deduced structure. The synthetic compound was identical to naturally occurring AB0022A.
New synthesis of biflavones of cupressuflavone series
作者:S. Ahmad、S. Razaq
DOI:10.1016/0040-4020(76)80071-3
日期:1976.1
7,7″-Dimethoxy cupressuflavone, 7,7″-dimethoxy 5,5″,4′,4‴-tetraacetoxy cupressuflavone, cupressuflavone hexamethylether and 7,7″,4′,4‴-tetramethoxy cupressuflavone have been synthesized by a new route via the corresponding bichalcones. It has the advantage over the synthesis via 8-iodo-apigenin trimethylether,2 that in the last step of demethylation of cupressuflavone hexamethylether, the possibility
Zirconium-redox-shuttled cross-electrophile coupling of aromatic and heteroaromatic halides
作者:Ting-Feng Wu、Yue-Jiao Zhang、Yue Fu、Fang-Jie Liu、Jian-Tao Tang、Peng Liu、F. Dean Toste、Baihua Ye
DOI:10.1016/j.chempr.2021.06.007
日期:2021.7
palladium-catalyzed processes. The zirconaaziridine-mediated palladium (ZAPd)-catalyzed reaction shows excellent compatibility with various functional groups and diverse heteroaromatic scaffolds. In accord with density functional theory (DFT) calculations, a redox transmetallation between the oxidativeaddition product and the zirconaaziridine is proposed as the crucial elementary step. Thus, cross-coupling selectivity
The nitration of substituted ethylbenzenes and substituted biphenyls
作者:AH Clemens、MP Hartshorn、KE Richards、GJ Wright
DOI:10.1071/ch9770103
日期:——
Nitration occurs ipso to
the ethyl group for p-ethyltoluene, p- diethylbenzene and ethylmesitylene. No
evidence was found for ipso- nitration for 2,4,6-trimethyl-, 4-methoxy-,
4-bromo- and 2,2',4,4',6,6'-hexamethoxy-biphenyls.
Anodic Phenol-Arene Cross-Coupling Reaction on Boron-Doped Diamond Electrodes
作者:Axel Kirste、Gregor Schnakenburg、Florian Stecker、Andreas Fischer、Siegfried R. Waldvogel
DOI:10.1002/anie.200904763
日期:2010.1.25
Particularly sustainable: The anodiccross‐couplingreaction between phenols and arenes can be performed on boron‐doped diamond electrodes. The arylated products are formed directly and obtained, in some cases, with high selectivity. Since only hydrogen atoms are sacrificed in the course of reaction this methodology opens the door to a novel concept for biaryl formation.