17574-14-0Relevant articles and documents
Esterification mechanism of lignin with different catalysts based on lignin model compounds by mechanical activation-assisted solid-phase synthesis
Zhao, Xiaohong,Zhang, Yanjuan,Wei, Liping,Hu, Huayu,Huang, Zuqiang,Yang, Mei,Huang, Aimin,Wu, Juan,Feng, Zhenfei
, p. 52382 - 52390 (2017)
In order to learn about the esterification mechanism of lignin by mechanical activation-assisted solid-phase synthesis (MASPS) technology, lignin model compounds, p-hydroxy benzaldehyde (H), vanillin and vanillyl alcohol (G), and syringaldehyde (S), were used in the reaction with acetic anhydride, with 4-dimethyl amino pyridine (DMAP), sodium acetate, and sulfuric acid as catalysts. FTIR, NMR, and UV/vis analyses of the products showed that all of the catalysts could enhance the esterification. Both the phenolic hydroxyl and aliphatic hydroxyl participated in the esterification and the reactivity of the basic structural units of lignin had a descending order of H, G, and S. Oxidations could happen in the presence of unsaturated groups such as aldehyde in the lignin model compounds. The catalytic mechanism of the three kinds of catalyst was different, and the catalytic activity had a descending order of DMAP, sodium acetate, and sulfuric acid. The reactivity of phenolic hydroxyl was higher than that of aliphatic hydroxyl with DAMP as the catalyst, but the reactivity of aliphatic hydroxyl was higher than that of phenolic hydroxyl with sodium acetate or sulfuric acid as the catalyst. With sulfuric acid as the catalyst, some side reactions took place and resulted in the ring cleavage or cross-linking of the benzene ring. Consistency verification indicated that the use of lignin model compounds for studying the esterification mechanism of lignin was reasonable and feasible.
[InCl4]: An efficient catalyst-medium for alkoxymethylation of alcohols and their interconversion to acetates and TMS-ethers
Mohammadpoor-Baltork, Iraj,Moghadam, Majid,Tangestaninejad, Shahram,Mirkhani, Valiollah,Khosropour, Ahmad Reza,Mirjafari, Arsalan
, p. 568 - 579 (2012/05/05)
A simple, green and chemoselective method for methoxymethylation and ethoxymethylation of primary and secondary alcohols using a Lewis acidic room temperature ionic liquid, [C4mim][InCl4], as catalyst and reaction medium under ambient temperature, microwave and ultrasonic irradiations is reported. In this catalytic system, the corresponding MOM-and EOM-ethers are obtained in excellent yields and in short reaction times. Furthermore, this catalytic system was used for mild and efficient transformations of these protected alcohols to their corresponding acetates and trimethylsilyl ethers under thermal conditions and microwave and ultrasonic irradiations.
CONVERSION OF METHYLENEDIOXYBENZENE DERIVATIVES INTO 2-METHOXYPHENOL DERIVATIVES
Takano, Seiichi,Akiyama, Masashi,Ogasawara, Kunio
, p. 2237 - 2238 (2007/10/02)
Methylenedioxybenzene derivatives are reductively cleft with diisobutylaluminum hydride to give 2-methoxyphenol derivatives.Concurrent hydroalumination occures when a substrate contains an olefinic bond in a side chain.
