A rapid and efficient synthesis of novel dendrimer homotriptycenes is presented. The dendronized 9,10-dihydroanthracen-9-ols 4, having high electron densities in the benzene rings of the Fréchet-type dendrons, exhibited in the presence of acid a quantitative transannular ring closure to the corresponding dendritic homotriptycenes. The electron-donating Fréchet-type dendrons enabled the intramolecular FC alkylation by a regioselective 1,7-elimination of H2O.
Lespedezavirgatol,a novel 2-phenylbenzofuran compound which was isolated from Lespedeza virgata,was firstly synthesized from pyrogallic acid and 3,4-dimethoxyphenol as starting materials with 8 steps.The key steps for the total synthesis were the selective iodination at 3-position of 1,2-dimethoxy-4-methoxymethoxybenzene and the Sonogashira cross-coupling reaction between 4-iodo-2-methoxybenzene-1,3-diol and 2-ethynyl-3,4-dimethoxy-1-(methoxy-methoxy)-benzene.
QI JinPing 1,DENG HongZhu 2 & CAO DeRong 1 1 School of Chemistry and Chemical Engineering,South China University of Technology,Guangzhou 510640,China 2 School of Traditional Chinese Medicine,Southern Medical University,Guangzhou 510515,China
A novel three-component copolymer (PFDP),derived from 9,9-dihexylfluorene,diketopyrrolopyrrole(DPP),and 10-octylphenothiazine,was synthesized through palladium-catalyzed Suzuki polycondensation in good yields. PFDP possessed moderate molecular weight and polydispersity,well-defined structure,and excellent thermal properties with an onset decomposition temperature at 357℃. PFDP in thin film exhibited red photoluminescence from DPP chromophore exclusively,with a peak at 602 nm. Electron-rich phenothiazine units sighificantly improved the injection and transport of holes by incorporating into polymer backbone. Light-emitting device was fabricated in the ITO/PEDOT:PSS/PVK/ polymer/Ba/Al configuration using PFDP as the emitting layer. The device based on PFDP showed red emission [CIE coordinate value (0.62,0.38)] that was close to the standard red (0.66,0.34). The results on electroluminescent performance revealed that PFDP may be a promising candidate for the red emitter with a maximum brightness of 259 cd/m2 and a maximum external quantum efficiency of 0.25%.
