无溶剂条件下煤基活性炭负载硫酸作为固体酸催化合成 14-烷基(芳基)-14H-二苯并[a,j]氧杂蒽类化合物

以自制的煤基活性炭负载硫酸为催化剂, β-萘酚、醛和脂肪醛为原料, 用一锅法成功合成了11个14-烷基(芳基)-14H-二苯并[a,j]氧杂蒽类化合物, 反应时间0.1～1 h, 收率71%～96%. 该方法不仅反应时间短, 产率高, 而且催化剂价廉易得, 对环境友好, 可重复利用5次, 活性没有明显降低, 并测得催化剂的酸值为3.06 mmol/g.     

离子液体1-乙基-3-丁基磺酸咪唑对甲苯磺酸盐催化合成氧杂蒽

以1-乙基咪唑为原料,合成了布朗斯特酸性离子液体--1-乙基-3-丁基磺酸咪唑对甲苯磺酸盐(IL1),并将其用于催化芳香醛与5,5-二甲基-1,3-环己二酮或1,3-环己二酮在无溶剂条件下合成了系列氧杂蒽类化合物,其结构经¹H NMR, ¹³C NMR和ESI-MS表征。研究结果表明：当IL1用量为5 mol%,于80 ℃反应40 min,收率78%~95%; IL1循环使用3次,收率86%~89%,催化活性无明显变化。     

PHOTO-INDUCED INTERMOLECULAR AND INTRAMOLECULAR ELECTRON-TRANSFER REACTIONS BETWEEN XANTHENE DYES AND DONORS/ACCEPTORS

A number of electron donors, acceptors and diads containing xanthene dyes were sythesized. When the dyes were excited, the rate constants and the efficiencies of the intermolecular and intramolecular photo-induced electron transfer reactions were determined and calculated. It is found that the photo-induced electron transfer reactions occurred between xanthene dyes and many, including very weak donors or acceptors. The rate constants of intermolecular reactions were controlled by diffusion, and influenced by the reactant concentrations. The laser flash experiments showed that for low reactant concentrations, this kind of reactions took place mainly via the triplet excited state of the dyes. If different electric charges exist with dyes and donors/acceptors, there will be static quenching of the dyes' fluorescence. The intramolecular electron transfer reactions are independent of the solution concentrations, and they may directly proceed via the singlet excited state of the dyes effectively.     

Hydrotrope induced synthesis of 1,8-dioxo-octahydroxanthenes in aqueous medium

Abstract

Hydrotrope induced synthesis of 1,8-dioxo-octahydroxanthenes from aromatic aldehydes and dimedone/1,3-cyclohexadione in aqueous medium is reported. The remarkable features of the new procedure are high conversions, shorter reaction times, cleaner reaction profiles, and simple experimental and work-up procedures.     

Surface modification of inorganic oxide particles with silane coupling agent and organic dyes

The silane coupling agent 3‐glycidoxypropyl trimethoxylsilane (GPS) was grafted onto the surface of silica gel, P ₂ glass beads and TiO ₂ oxide particles. FT‐IR, thermogravimetric and elemental analysis were used to characterize the modified particles. The effects of various factors on the GPS grafting efficiency such as catalyst, GPS concentration, reaction temperature and time were studied. After modification with GPS, the xanthene dye rhodamine B and azo dyes 4‐phenylazophenol and 4‐phenylazoaniline, respectively, were grafted on to the particles, which were then used as pigment fillers. The colors of the pigments were adjusted by changing the kind of dyes, the concentration, the pH and the reaction solvents. Copyright © 2001 John Wiley & Sons, Ltd.     

H5PW（10）V2O40催化高效环保合成14-芳基-14H-二苯并[a,j]氧杂蒽（英文）

A rapid and efficient procedure for the preparation of various aryl-14H-dibenzo[a,j]xanthenes was reported.The method developed produced excellent yields via one-pot condensation of β-naphthol with various aryl-aldehydes in the presence of Keggin vanadium substituted heteropolyacid,H5PW10V2O40,as catalyst under solvent free conditions.The present methodology therefore offered several advantages but not limited to excellent yields(82%-98%),short reaction times(30-50 min),mild reaction conditions,simple work-up,as well as the utilization of cheap and environmentally benign catalyst in the absence of organic solvents.     

新型五氟苯铵三氟有机催化剂高效合成14-芳基(烷基)-14H-二苯并[a,j]呫吨类化合物和1,8-二氧代氧杂蒽衍生物(英文)

A simple and facile synthesis of 14-aryl and alkyl-14H-dibenzo[a,j]xanthenes and 1,8-dioxooctahydroxanthene derivatives has been successfully developed by treatment of β-naphthol or dimedone with aldehydes under mild conditions in the presence of a pentafluorophenyl ammonium triflate(PFPAT) organocatalyst.These catalytic condensation reactions represent green chemical processes and the PFPAT organocatalyst is air-stable,cost-effective,easy to handle,and easily removed from the reaction mixtures.     

A novel class of organosoluble poly(arylene ether nitrile) copolymers containing methyl substituent and cardo xanthene moiety

9,9‐Bis(3‐methyl‐4‐hydroxyphenyl)xanthene (BMHPX) was synthesized in 72% yield by a HCl/ZnCl₂‐catalyzed condensation reaction of xanthenone with excess o‐cresol. Based on this new bisphenol monomer, a series of poly(arylene ether nitrile) (PAEN) and PAEN copolymers containing methyl substituent and cardo xanthene moiety were prepared by the nucleophilic substitution reaction of 2,6‐difluorobenzonitrile (DFBN) with BMHPX and with varying mole proportions of BMHPX to hydroquinone (HQ) (100/0–40/60) using N‐methyl‐2‐pyrrolidone (NMP) as solvent in the presence of anhydrous potassium carbonate. These polymers had inherent viscosities between 0.54 and 0.72 dl/g, and their weight‐average molecular weights and number‐average molecular weights were in the range of 32,600–36,400 and 17,300–18,300, respectively. All PAENs were amorphous and were soluble in dipolar aprotic solvents such as NMP and N,N‐dimethylacetamide (DMAc), and even in THF and chloroform at room temperature. The resulting polymers showed glass transition temperatures (T_g's) between 213–226°C, and the T_g values of the copolymers were found to increase with increase of the BMHPX units content in the polymer. Thermogravimetric studies showed that all the polymers were stable up to 404°C, with 10% weight loss temperatures ranging from 444 to 455°C, and char yields of 52–58% at 700°C in nitrogen. All new PAENs could be cast into transparent, strong, and flexible films with tensile strengths of 102–120 MPa, elongations at break of 14–18%, and tensile moduli of 3.3–3.7 GPa. Copyright © 2011 John Wiley & Sons, Ltd.     

Bite Angle Effects in Hydroformylation Catalysis

Recent advances in rhodium catalyzed hydroformylation using xanthene‐based ligands will be reviewed. The calculated natural bite angles of the ligands discussed are in the range 100–123°. While the general trend is clear—higher 1: b ratios at wider angles, small changes in the bite angle do not exhibit a regular effect on the selectivity of the reaction. The same is true for the rate of CO dissociation; the larger the rate of the CO dissociation, the larger the rate of hydroformylation, but for small changes the effects do not comply with this rule.