Catalytic decomposition of 1,3-diphenoxybenzene to monomeric cyclic compounds over palladium catalysts supported on acidic activated carbon aerogels
摘要:
Activated carbon aerogel (ACA) was prepared by a chemical activation of carbon aerogel using phosphoric acid (H3PO4). Activated carbon aerogel bearing sulfonic acid (ACA-SO3H), Cs2.5H0.5PW12O40-impregnated activated carbon aerogel (Cs2.5H0.5PW12O40/ACA), and Cs2.5H0.5PW12O40-impregnated activated carbon aerogel bearing sulfonic acid (Cs2.5H0.5PW12O40/ACA-SO3H) were prepared in order to provide acid sites to ACA. Palladium catalysts were then supported on ACA, ACA-SO3H, Cs2.5H0.5PW12O40/ACA, and Cs2.5H0.5PW12O40/ACA-SO3H by an incipient wetness impregnation method. The prepared Pd/ACA, Pd/ACA-SO3H, Pd/Cs2.5H0.5PW12O40/ACA, and Pd/Cs2.5H0.5PW12O40/ACA-SO3H catalysts were applied to the decomposition of 1,3-diphenoxybenzene. 1,3-Diphenoxybenzene was used as a trimeric lignin model compound for representing C-O bond in lignin. Cyclohexanol, benzene, and phenol were mainly produced by the decomposition of 1,3-diphenoxybenzene. 4-Phenoxyphenol was also produced as an intermediate by the decomposition of 1,3-diphenoxybenzene. Conversion of 1,3-diphenoxybenzene and total yield for main products (cyclohexanol, benzene, and phenol) increased with increasing acidity of the catalysts. Among the catalysts tested, Pd/Cs2.5H0.5PW12O40/ACA-SO3H with the largest acidity showed the highest conversion of 1,3-diphenoxybenzene and total yield for main products. Pd/Cs2.5H0.5PW12O40/ACA-SO3H also served as a stable and reusable catalyst in the decomposition of 1,3-diphenoxybenzene. (C) 2013 Elsevier B.V. All rights reserved.
A new development in the chemistry of arenes activated toward S(N)Ar reactions by the cyclopentadienyliron (FeCp+) moiety is presented in this work. A class of diiron complexes of diphenoxybenzenes was prepared in a highly efficient and very mild fashion. Dihydroxyaromatic compounds served as dinucleophiles, allowing for the formation of the diiron complexes. This could be achieved in either a one or two step procedure. A wide variety of dinucleophiles were incorporated into this study, as well as a number of FeCp+ activated arenes. It is shown that these reactions are not inhibited by bulky substituents on either the dinucleophiles or activated arenes. The diiron complexes themselves could also undergo S(N)Ar reactions, provided that the complexed arenes contained a chlorine substituent. This allowed for the functionalization of the complexes with species that could not be introduced directly in their syntheses. The carbon nucleophiles generated from ethyl cyanoacetate or (phenylsulfonyl)acetonitrile could be attached to the complexed ethers in this manner. The FeCp+ moieties were removed easily by photolytic demetalation which allowed for the recovery of a wide range of functionalized diphenoxybenzenes. This methodology is advantageous over all those previously reported and should be a practical route to the synthesis of aromatic ethers.
Fenbufen, a New Anti-Inflammatory Analgesic: Synthesis and Structure-Activity Relationships of Analogs
作者:Ralph G. Child、Arnold C. Osterberg、Adolph E. Sloboda、Andrew S. Tomcufcik
DOI:10.1002/jps.2600660403
日期:1977.4
hundred analogs of fenbufen were prepared and tested using the carrageenan, polyarthritis, and UV erythema anti-inflammatory tests and the 2-phenyl-1,4-benzoquinone writhing and inflamed paw pressure analgesic tests. Only three retained the same full spectrum of activity as fenbufen: dl-4-(4-biphenylyl)-4-hydroxybutyric acid, dl-4-(4-biphenylyl)-1,4-butanediol, and 4-biphenylacetic acid. Fenbufen had the
SUBSTITUTED OR UNSUBSTITUTED ALLYL GROUP-CONTAINING MALEIMIDE COMPOUND, PRODUCTION METHOD THEREFOR, AND COMPOSITION AND CURED PRODUCT USING SAID COMPOUND
申请人:DIC CORPORATION
公开号:US20200325101A1
公开(公告)日:2020-10-15
Bismaleimides (BMI) exhibit excellent heat resistance (high Tg and high resistance to thermal decomposition) compared to epoxy resins and phenolic resins, and therefore, in recent years, more attention is paid to bismaleimides as a resin material for the next-generation devices represented by SiC power semiconductors, in addition to the investigation on the use of bismaleimides for electronic material applications. As such, conventional BMI's are known as highly heat-resistant resins; however, there is a demand for a resin having higher heat resistance for advanced material applications and the like. Thus, an object of the invention is to provide a novel maleimide compound having superior heat resistance. Disclosed is a substituted or unsubstituted allyl group-containing maleimide compound having a structure with three or more benzene rings, having one or more groups each having a substituted or unsubstituted allyl group, and having one or more maleimide groups.
A stable and practical nickel catalyst for the hydrogenolysis of C–O bonds
作者:Xinjiang Cui、Hangkong Yuan、Kathrin Junge、Christoph Topf、Matthias Beller、Feng Shi
DOI:10.1039/c6gc01955b
日期:——
The selective hydrogenolysis of C-O bonds constitutes a key step for the valorization of biomass including lignin fragments.
CO键的选择性氢解构成了包括木质素片段的生物质的增值的关键步骤。
Formal Cross-Coupling of Diaryl Ethers with Ammonia by Dual C(Ar)–O Bond Cleavages
作者:Dawei Cao、Huiying Zeng、Chao-Jun Li
DOI:10.1021/acscatal.8b02214
日期:2018.9.7
inorganic chemical. Herein, we report a direct conversion of diaryl ethers and ammonia into aniline derivatives and arenes, providing a model for selective lignin 4-O-5 linkage modification and PPO recycling with inexpensive ammonia. Both symmetrical and unsymmetrical diaryl ethers were successfully cross-coupled with ammonia via dual C(Ar)–O bond cleavages, generating the corresponding cyclohexylanilines