22347-47-3Relevant articles and documents
Au NPs@ polystyrene resin for mild and selective aerobic oxidation of 1,4 dioxane to 1,4 dioxan-2-ol
Sharma, Anuj S.,Kaur, Harjinder
, p. 56 - 59 (2017)
Supported gold nanoparticles of sizes 5–8 nm have been found as highly efficient catalyst for the oxidation of 1,4 dioxane, a saturated ether, using elemental oxygen at low temperature. GC–MS analysis of the reaction mixture showed > 85% conversion of 1,4 dioxane with a TON of 1120 h? 1 to 1,4 dioxan-2-ol with 90% selectivity. 1,4 Dioxan-2-one was obtained as the major byproduct along with traces of acetic acid and methoxy dioxalane. The catalyst displayed excellent stability and recyclability. TEM analysis of reused catalyst indicated that there was no significant change in the size, shape and morphology of gold nanoparticles.
Oxidation of Substituted Alkyl Radicals by IrCl62-, Fe(CN)63-, and MnO4- in Aqueous Solution. Electron Transfer versus Chlorine Transfer from IrCl62-
Steenken, S.,Neta, P.
, p. 1244 - 1248 (1982)
Alkyl radicals substituted at Cα by alkyl, carboxyl, hydroxyl, alkoxyl, and chlorine react in aqueous solutions with IrIVCl62- to yield Ir(III) species.In the case of substitution by hydroxyl and alkoxyl, the rate constants are in the diffusion-controlled range ((4-6)x109 M-1 s-1) and the reaction proceeds by electron transfer.In the case of ethyl, methyl, carboxymethyl, and chloromethyl radicals the rate constants range from 3.1x109 for ethyl to 2.8x107 M-1 s-1 for trichloromethyl and the reaction proseeds by chlorine transfer from IrCl62- to the alkyl radical.With isopropyl and tert-butyl radicals the reaction proceeds by both electron and chlorine transfer.Alkyl radicals also react with Fe(CN)63-.The rate constants increase strongly with increasing alkylation at Cα from 5x106 for methyl to 3.6x109 M-1 s-1 for tert-butyl, indicating that the transition state for the reaction is highly polar.Rate constants for reaction of MnO4- with alkyl radical are of the order 109 M-1 s-1.
Production of Hydroxy Acids: Selective Double Oxidation of Diols by Flavoprotein Alcohol Oxidase
Fraaije, Marco W.,Martin, Caterina,Trajkovic, Milos
, p. 4869 - 4872 (2020/02/11)
Flavoprotein oxidases can catalyze oxidations of alcohols and amines by merely using molecular oxygen as the oxidant, making this class of enzymes appealing for biocatalysis. The FAD-containing (FAD=flavin adenine dinucleotide) alcohol oxidase from P. chrysosporium facilitated double and triple oxidations for a range of aliphatic diols. Interestingly, depending on the diol substrate, these reactions result in formation of either lactones or hydroxy acids. For example, diethylene glycol could be selectively and fully converted into 2-(2-hydroxyethoxy)acetic acid. Such a facile cofactor-independent biocatalytic route towards hydroxy acids opens up new avenues for the preparation of polyester building blocks.
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.
Flavin Nitroalkane Oxidase Mimics Compatibility with NOx/TEMPO Catalysis: Aerobic Oxidization of Alcohols, Diols, and Ethers
Thapa, Pawan,Hazoor, Shan,Chouhan, Bikash,Vuong, Thanh Thuy,Foss, Frank W.
, p. 9096 - 9105 (2020/08/14)
Biomimetic flavin organocatalysts oxidize nitromethane to formaldehyde and NOx - providing a relatively nontoxic, noncaustic, and inexpensive source for catalytic NO2 for aerobic TEMPO oxidations of alcohols, diols, and ethers. Alcohols were oxidized to aldehydes or ketones, cyclic ethers to esters, and terminal diols to lactones. In situ trapping of NOx and formaldehyde suggest an oxidative Nef process reminiscent of flavoprotein nitroalkane oxidase reactivity, which is achieved by relatively stable 1,10-bridged flavins. The metal-free flavin/NOx/TEMPO catalytic cycles are uniquely compatible, especially compared to other Nef and NOx-generating processes, and reveal selectivity over flavin-catalyzed sulfoxide formation. Aliphatic ethers were oxidized by this method, as demonstrated by the conversion of (-)-ambroxide to (+)-sclareolide.
Pd-Catalyzed Aerobic Oxidation Reactions: Strategies to Increase Catalyst Lifetimes
Ho, Wilson C.,Chung, Kevin,Ingram, Andrew J.,Waymouth, Robert M.
supporting information, p. 748 - 757 (2018/01/26)
The palladium complex [(neocuproine)Pd(μ-OAc)]2[OTf]2 (1, neocuproine = 2,9-dimethyl-1,10-phenanthroline) is an effective catalyst precursor for the selective oxidation of primary and secondary alcohols, vicinal diols, polyols, and carbohydrates. Both air and benzoquinone can be used as terminal oxidants, but aerobic oxidations are accompanied by oxidative degradation of the neocuproine ligand, thus necessitating high Pd loadings. Several strategies to improve aerobic catalyst lifetimes were devised, guided by mechanistic studies of catalyst deactivation. These studies implicate a radical autoxidation mechanism initiated by H atom abstraction from the neocuproine ligand. Ligand modifications designed to retard H atom abstractions as well as the addition of sacrificial H atom donors increase catalyst lifetimes and lead to higher turnover numbers (TON) under aerobic conditions. Additional investigations revealed that the addition of benzylic hydroperoxides or styrene leads to significant increases in TON as well. Mechanistic studies suggest that benzylic hydroperoxides function as H atom donors and that styrene is effective at intercepting Pd hydrides. These strategies enabled the selective aerobic oxidation of polyols on preparative scales using as little as 0.25 mol % of Pd, a major improvement over previous work.
Copper-catalyzed, stereoconvergent,: Cis -diastereoselective borylative cyclization of ω -mesylate- α, β -unsaturated esters and ketones
Zuo, Ya-Jie,Chang, Xiao-Tong,Hao, Zhi-Ming,Zhong, Chong-Min
supporting information, p. 6323 - 6327 (2017/08/10)
The Cu(i)-catalyzed stereoconvergent borylative cyclization of ω-mesylate-α,β-unsaturated compounds is facilitated by a simple Cu-bisphosphine catalyst. This reaction provides a novel route to cis-β-boron-substituted five- and six-membered carbocycle and heterocycle esters. Mechanistic studies indicate that stereoconvergence and cis-substitution likely stem from the rapid enolation of the borylcopper adduct with the substrate double bond and the formation of a five-membered intermediate, respectively.
Efficient and Selective Cu/Nitroxyl-Catalyzed Methods for Aerobic Oxidative Lactonization of Diols
Xie, Xiaomin,Stahl, Shannon S.
supporting information, p. 3767 - 3770 (2015/04/14)
Cu/nitroxyl catalysts have been identified that promote highly efficient and selective aerobic oxidative lactonization of diols under mild reaction conditions using ambient air as the oxidant. The chemo- and regioselectivity of the reaction may be tuned by changing the identity of the nitroxyl cocatalyst. A Cu/ABNO catalyst system (ABNO = 9-azabicyclo[3.3.1]nonan-N-oxyl) shows excellent reactivity with symmetrical diols and hindered unsymmetrical diols, whereas a Cu/TEMPO catalyst system (TEMPO = 2,2,6,6-tetramethyl-1-piperidinyl-N-oxyl) displays excellent chemo- and regioselectivity for the oxidation of less hindered unsymmetrical diols. These catalyst systems are compatible with all classes of alcohols (benzylic, allylic, aliphatic), mediate efficient lactonization of 1,4-, 1,5-, and some 1,6-diols, and tolerate diverse functional groups, including alkenes, heterocycles, and other heteroatom-containing groups.
(Meth)acrylate derivative, intermediate thereof, and polymer compound
-
Page/Page column 67; 68, (2013/07/25)
Provided are a polymerizable compound shown below which is useful as a raw material for a polymer having less swelling in developing, a polymer obtained by polymerizing a raw material containing the above polymerizable compound, a photoresist composition which contains the above polymer and which is improved in LWR and an efficient production process for the polymerizable compound described above: wherein n represents an integer of 0 to 2; R1 represents a hydrogen atom, methyl or trifluoromethyl; R2, R3, R4, R5, R6, R7, R8, R9 and R10 represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or the like; W represents an alkylene group having 1 to 10 carbon atoms or the like; and Y1 and Y2 represent an oxygen atom or a sulfur atom.
ACRYLATE ESTER DERIVATIVES AND POLYMER COMPOUNDS
-
Page/Page column 79-80, (2013/02/27)
A cyclic alcohol of formula (II-1): wherein: R2, R3, and R4 are each independently a hydrogen atom, a linear alkyl group comprising 1 to 6 carbon atoms, a branched alkyl group comprising 3 to 6 carbon atoms, or a cyclic alkyl group comprising 3 to 6 carbon atoms; or R2 and R3 or R3 and R4 combine to form an alkylene group comprising 3 to 6 carbon atoms; m is 1 or 2; R5, R6, R7, R8, R9, and R10 are each independently a hydrogen atom, a linear alkyl group comprising 1 to 6 carbon atoms, a branched alkyl group comprising 3 to 6 carbon atoms, or a cyclic alkyl group comprising 3 to 6 carbon atoms; A is an oxygen atom; and B is an oxygen atom or a sulfur atom. In addition, a process for producing the cyclic alcohol of formula (II-1).
