447-61-0Relevant articles and documents
Efficient and selective oxidation of benzylic alcohol by O2 into corresponding aldehydes on a TiO2 photocatalyst under visible light irradiation: Effect of phenyl-ring substitution on the photocatalytic activity
Higashimoto, Shinya,Suetsugu, Nobuaki,Azuma, Masashi,Ohue, Hiroyoshi,Sakata, Yoshihisa
, p. 76 - 83 (2010)
The highly efficient and selective photocatalytic oxidation of benzyl alcohol and its derivatives substituted with-OCH3,-CH 3,-C(CH3)3,-Cl,-CF3 and-NO 2 into corresponding aldehydes has been successfully carried out on TiO2 in the presence of O2 under visible light irradiation. The photocatalytic activity for the formation of the aldehyde was evaluated by a pseudo-first-order reaction, and it was found that the activity is enhanced by phenyl-ring substitution with the electron-releasing groups (-OCH3,-CH3,-C(CH3)3) and the electron-withdrawing groups (-Cl,-CF3 and-NO2). The effects of the substituents and their orientation on the photocatalytic performance of selective oxidation reaction are discussed here. It was shown that the photocatalytic activities are influenced not only by the oxidative potentials of the reactants but also by the stability of the resonant structures of the benzylic alcohol radicals formed by oxidation with a hole, leading to further reactions to form corresponding aldehydes.
Cerium(IV) Carboxylate Photocatalyst for Catalytic Radical Formation from Carboxylic Acids: Decarboxylative Oxygenation of Aliphatic Carboxylic Acids and Lactonization of Aromatic Carboxylic Acids
Hirosawa, Keishi,Mashima, Kazushi,Satoh, Tetsuya,Shinohara, Koichi,Shirase, Satoru,Tamaki, Sota,Tsurugi, Hayato
supporting information, (2020/03/25)
We found that in situ generated cerium(IV) carboxylate generated by mixing the precursor Ce(OtBu)4 with the corresponding carboxylic acids served as efficient photocatalysts for the direct formation of carboxyl radicals from carboxylic acids under blue light-emitting diodes (blue LEDs) irradiation and air, resulting in catalytic decarboxylative oxygenation of aliphatic carboxylic acids to give C-O bond-forming products such as aldehydes and ketones. Control experiments revealed that hexanuclear Ce(IV) carboxylate clusters initially formed in the reaction mixture and the ligand-to-metal charge transfer nature of the Ce(IV) carboxylate clusters was responsible for the high catalytic performance to transform the carboxylate ligands to the carboxyl radical. In addition, the Ce(IV) carboxylate cluster catalyzed direct lactonization of 2-isopropylbenzoic acid to produce the corresponding peroxy lactone and ?3-lactone via intramolecular 1,5-hydrogen atom transfer (1,5-HAT).
Selective Functionalization of Styrenes with Oxygen Using Different Electrode Materials: Olefin Cleavage and Synthesis of Tetrahydrofuran Derivatives
Imada, Yasushi,Okada, Yohei,Noguchi, Keiichi,Chiba, Kazuhiro
supporting information, p. 125 - 129 (2018/12/05)
Electrode materials can have a significant impact on the course of an electrolysis reaction. Of particular interest is that different electrodes can generate different products from the same substrate. The electrode-material-selective transformations of styrene derivatives with molecular oxygen are reported. Platinum electrodes afford carbonyl products via cleavage of olefins, whereas tetrahydrofuran formation is achieved with carbon electrodes. A variety of different styrenes are available for both reactions. Electrolysis allows straightforward and mild chemical conversions that are metal- and oxidant-free. Electrochemical measurements illuminate the different effects of platinum and carbon electrodes on styrenes. The key to the differing reactions is probably that the oxidation potentials of the substrates are lower (higher HOMO energy) on carbon electrodes than on platinum electrodes. The adsorption of the substrates on carbon electrodes can also promote tetrahydrofuran formation.