632-21-3Relevant articles and documents
Lignin-fueled photoelectrochemical platform for light-driven redox biotransformation
Boonmongkolras, Passarut,Choi, Eun-Gyu,Han, Seunghyun,Kim, Jinhyun,Kim, Kayoung,Kim, Yong Hwan,Lee, Sahng Ha,Lee, Yang Woo,Park, Chan Beum,Shin, Byungha,Trang, Nguyen Vu Thien,Wang, Ding
supporting information, p. 5151 - 5160 (2020/08/25)
The valorization of lignin has significant potential in producing commodity chemicals and fuels from renewable resources. However, the catalytic degradation of lignin is kinetically challenging and often requires noble metal catalysts to be used under harsh and toxic conditions. Here, we report the bias-free, solar reformation of lignin coupled with redox biotransformation in a tandem structure of a BiVO4 photoanode and perovskite photovoltaic. The tandem structure compensates for the potential gap between lignin oxidation and biocatalytic reduction through artificial Z-schematic absorption. We found that the BiVO4-catalyzed photoelectrochemical oxidation of lignin facilitated the fragmentation of higher molecular weight lignin into smaller carboxylated aliphatic and aromatic acids. Lignin oxidation induced photocurrent generation at the photoanode, which enabled efficient electroenzymatic reactions at the cathode. This study successfully demonstrates the oxidative valorization of lignin as well as biocatalytic reductions (e.g., CO2-to-formate and α-ketoglutarate-to-l-glutamate) in an unbiased biocatalytic PEC platform, which provides a new strategic approach for photo-biocatalysis using naturally abundant renewable resources.
Studies on the Mechanism of an Olefination of Aldehydes to 1,1-Bis(trifluoromethyl)alkenes
Korhummel, Claus,Hanack, Michael
, p. 2187 - 2192 (2007/10/02)
1,1-Bis(trifluoromethyl)olefins 3 are obtained from aldehydes, 2,2-dichlorohexafluoropropane (1), and triphenylphosphine.The mechanism of this olefination reaction is studied, and it is shown that it takes place not by Wittig- but by a Knoevenagel-type of reaction.Ketones react with 1 and triphenylphosphine to form olefins 3 only when they are activated by a CF3 group.Chlorosubstituted ketones, e.g. 1,1,1-trichloroacetone or hexachloroacetone, cannot be converted to the corresponding 1,1-bis(trifluoromethyl)olefins.Hexachloroacetone reacts with triphenylphosphine predominantely with formation of perchloroallene (24), which quantitatively dimerizes to form perchloro-1,2-dimethylenecyclobutane (25). - Key Words: Aldehyde olefination / Alkenes, 1,1-bis(trifluoromethyl)- / Olefination reaction