4166-86-3Relevant articles and documents
Synthesis of Ti-Al binary oxides and their catalytic application for C-H halogenation of phenols, aldehydes and ketones
Su, Peigen,Fan, Chao,Yu, Heng,Wang, Wanqin,Jia, Xin,Rao, Qifan,Fu, Chenxi,Zhang, Donghua,Huang, Benhua,Pan, Cheng,Zheng, Aqun,Sun, Yang
, (2019/06/13)
Traditional C–H halogenation of organic compounds often requires corrosive agent or harsh condition, and current researches are focused on the use of noble metals as catalyst. In order to give an efficient, benign, activity-adjustable and cost-effective system for halogenation, a series of Ti-Al mixed oxides are prepared as catalyst through sol-gel in this work. Characterizations reveal all catalysts contain more aluminum than titanium, but preparative conditions affect their composition and crystallinity. Monitoring of particle size, zeta potential and UV–vis of preparative solution reveals that formation of catalyst colloids undergoes chemical reaction, affecting catalyst morphology. In halogenation, all catalysts show moderate to high activities, copper chloride proves to be an effective halogen source rather than sodium chloride. The chlorination and bromination are better than iodization, phenol and ketone appear to be more appropriate substrates than aldehyde. Additionally, oxide backbone of catalyst is more durable than its organic components during recycling. This study may provide new catalytic materials for progress of C–H activation.
Synthesis and oxidizing ability of p-chloranil dimer
Hayashi, Naoto,Nakagawa, Hiroyuki,Sugiyama, Yuko,Yoshino, Junro,Higuchi, Hiroyuki
, p. 398 - 400 (2013/05/21)
A p-chloranil dimer ( pCh2) has been synthesized. The first reduction potential of pCh2 shifted to a more positive value than that observed for the p-chloranil monomer ( pCh1) and was more negative than that for 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ). As expected, pCh2 oxidized 9,10-dihydroanthracene and α-tetralol to give anthracene and α-tetralone, respectively, more efficiently than pCh1 did. The advantages of pCh2 were observed in oxidations of 2,4-di-tert-butylphenol and 2,6-di-tertbutyl- 4-methylphenol. Although further oxidation took place in DDQ oxidations and no reaction occurred in pCh1 oxidations, initial oxidation products were solely obtained in pCh2 oxidation because of its moderate oxidizing ability.
Cyclodienones. X. Reaction of Halo-cyclohexadien-1-ones with Phenols in the Presence of α-Picoline and Preparation of 4-Hydroxy- and 2-Hydroxyphenyl Aryl Ethers
Tashiro, Masashi,Itoh, Takashi,Fukata, Gouki
, p. 416 - 420 (2007/10/02)
Reaction of 4-halocyclohexadienones such as 4-bromo-(1a), 4-chloro-2,4,6-tri-t-butyl-(1b), 2,4-dichloro-4,6-di-t-butyl-2,5-cyclohexadien-1-one, and 2,4-dichloro-2,6-di-t-butyl-3,5-cyclohexadien-1-one with phenols in the presence of α-picoline was carried out under various conditions.The reaction of 1a and 1b with phenols afforded the corresponding 2-aryloxy-4,6-di-t-butyl phenols together with various by-products.The AlCl3 catalyzed trans-t-butylation of 2-aroxy-4,6-di-t-butyl-phenols, which were obtained by the above reaction, afforded the corresponding 2-hydroxyphenyl aryl ethers.The similar reaction of 4-aroxy-2,4,6-tri-t-butyl-2,5-cyclohexadien-1-ones also afforded the corresponding 4-hydroxyphenyl aryl ethers.
