3128-07-2Relevant academic research and scientific papers
Mixed crystals containing the dioxo complex [{Ph3SiO} 2VO2]- and novel pentacoordinated oxoperoxo complex [{Ph3SiO}2- VO(O2)]-: X-ray crystal structure and assessment as oxidation catalysts
Vennat, Maxence,Bregeault, Jean-Marie,Herson, Patrick
, p. 908 - 913 (2004)
[n-Bu4N][{Ph3SiO}2VO2] reacts with H2O2 tomixed-crystal yield an oxoperoxo complex which crystallizes as a mixed-crystal compound, [P(C6H5) 4][{(C6H5)3 SiO}2VO 2]x[{(C6H5)3 SiO} 2VO(O2)]1-x, 1 (x = 0.57). It has been characterized by elemental analysis and spectroscopy (51V NMR, UV-visible and IR). The X-ray structure analysis reveals the presence of two interrelated anions: [{Ph3SiO}2VvO 2]-, 1a, and [{Ph3SiO}2V vO(O2)]-, 1b with a cisoid geometry of the (VO(O2)}+ moiety. The two structures differ only slightly: anion 1a exhibits unusual tetrahedral coordination around the vanadium centre found in the precursor, whereas the geometry at the metal ion in 1b can be described as a trapezoidal pyramid. Steric constraints due to Ph 3SiO- ligands and PPh4+ cations are responsible for this geometry. The reactivity of 1 in the C-C bond cleavage of 2-methylcyclohexanone under anaerobic conditions has been studied. The results suggest that peroxygen species are involved in the oxidative cleavage of C-C bonds of cycloalkanones.
Visible Light-Driven, Copper-Catalyzed Aerobic Oxidative Cleavage of Cycloalkanones
Xin, Hong,Duan, Xin-Hua,Yang, Mingyu,Zhang, Yiwen,Guo, Li-Na
, p. 8263 - 8273 (2021/06/30)
A visible light-driven, copper-catalyzed aerobic oxidative cleavage of cycloalkanones has been presented. A variety of cycloalkanones with varying ring sizes and various α-substituents reacted well to give the distal keto acids or dicarboxylic acids with moderate to good yields.
Azolium/Hydroquinone Organo-Radical Co-Catalysis: Aerobic C?C-Bond Cleavage in Ketones
Nakatsuji, Yuya,Kobayashi, Yusuke,Masuda, Sakyo,Takemoto, Yoshiji
supporting information, p. 2633 - 2637 (2021/02/03)
Organo-radical catalysts have recently attracted great interest, and the development of this field can be expected to broaden the applications of organocatalysis. Herein, the first example of a radical-generating system is reported that does not require any photoirradiation, radical initiators, or preactivated substrates. The oxidative C?C-bond cleavage of 2-substituted cyclohexanones was achieved using an azolium salt and a hydroquinone as co-catalysts. A catalytic mechanism was proposed based on the results of diffusion-ordered spectroscopy and cyclic voltammetry measurements, as well as computational studies.
Selective C-C Bond Cleavage of Cycloalkanones by NaNO2/HCl
He, Tianyu,Chen, Dengfeng,Qian, Shencheng,Zheng, Yu,Huang, Shenlin
supporting information, p. 6525 - 6529 (2021/09/02)
A novel selective fragmentation of cycloalkanones by NaNO2/HCl has been established. The C-C bond cleavage reaction proceeds smoothly under mild conditions, selectively affording versatile keto acids or oxime acids. The methodology can streamline the synthesis of valuable chiral molecules and isocoumarins from readily available feedstocks.
Catalytic oxidation of α-substituted cyclohexanone with steric hindrance to 6-oxohexanoic acid involved during the total synthesis of (+)-biotin
Li, Haoran,Ma, Qiyi,Mao, Jianyong,Yao, Jia,Yuan, Haoran
, (2021/08/13)
A homogeneous catalyst system FeCl3/DMSO was developed to catalyze α-substituted cyclohexanone to corresponding 6-oxohexanoic acid, an important intermediate involved during the synthesis of (+)-biotin. A highly efficient oxidation with 95.3 % of conversion and 88.0 % of selectivity was achieved using oxygen as the oxidant, which shows great advantage over the traditional peroxide method from industrial aspects. The detailed reaction process was evaluated to determine the parallel reactions scheme consisted by two oxidative reactions and one chlorination reaction. The [Fe(DMSO)4Cl2]Cl complex detected by UV–vis and FT-IR spectrometer was proposed as the active component during the catalytic process. The control experiments, capture of important intermediates, and kinetic study were performed, which showed the oxidation proceeded via the combination of ionic and radical pathway. The FeCl3/DMSO can be recycled with minor yield loss.
Synthesis of Carboxylic Acids by Palladium-Catalyzed Hydroxycarbonylation
Sang, Rui,Kucmierczyk, Peter,Dühren, Ricarda,Razzaq, Rauf,Dong, Kaiwu,Liu, Jie,Franke, Robert,Jackstell, Ralf,Beller, Matthias
supporting information, p. 14365 - 14373 (2019/09/06)
The synthesis of carboxylic acids is of fundamental importance in the chemical industry and the corresponding products find numerous applications for polymers, cosmetics, pharmaceuticals, agrochemicals, and other manufactured chemicals. Although hydroxycarbonylations of olefins have been known for more than 60 years, currently known catalyst systems for this transformation do not fulfill industrial requirements, for example, stability. Presented herein for the first time is an aqueous-phase protocol that allows conversion of various olefins, including sterically hindered and demanding tetra-, tri-, and 1,1-disubstituted systems, as well as terminal alkenes, into the corresponding carboxylic acids in excellent yields. The outstanding stability of the catalyst system (26 recycling runs in 32 days without measurable loss of activity), is showcased in the preparation of an industrially relevant fatty acid. Key-to-success is the use of a built-in-base ligand under acidic aqueous conditions. This catalytic system is expected to provide a basis for new cost-competitive processes for the industrial production of carboxylic acids.
Colloidal tectonics for tandem synergistic Pickering interfacial catalysis: Oxidative cleavage of cyclohexene oxide into adipic acid
Yang, Bingyu,Leclercq, Lo?c,Schmitt, Véronique,Pera-Titus, Marc,Nardello-Rataj, Véronique
, p. 501 - 507 (2019/01/10)
Supramolecular preorganization and interfacial recognition can provide useful architectures for colloidal building. To this aim, a novel approach, based on colloidal tectonics involving two surface-active particles containing both recognition and catalytic sites, has been developed for controlling the formation and the properties of Pickering emulsions. This was illustrated by the combination of dodecyltrimethylammonium phosphotungstate nanoparticles, [C12]3[PW12O40], and silica particles functionalized with alkyl and sulfonic acid groups, [Cn/SO3H]@SiO2. The interfacial self-assembly occurs by the penetration of the alkyl chains of [Cn/SO3H]@SiO2 into the [C12]3[PW12O40] supramolecular porous structure constituted of polar and apolar regions. The emulsions were used as a non-nitric acid route for adipic acid synthesis from the one-pot oxidative cleavage of cyclohexene oxide with aqueous H2O2. The catalytic performance was significantly boosted due to the synergistic interactions between the particles.
OXIDATIVE CLEAVAGE OF OLEFINS, EPOXIDES AND ALCOHOLS
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Page/Page column 23, (2019/02/06)
Provided is a process for producing a compound I comprising at least one functional group chosen in the group consisting of epoxy group, hydroxyl group and carbonyl group and by reacting a compound J comprising at least one functional group chosen in the group consisting of alkenyl group, epoxy group and hydroxyl group with an an oxidant in the presence of solid amphiphilic catalytic particles A and solid amphiphilic catalytic particles B.
An efficient method for retro-Claisen-type C-C bond cleavage of diketones with tropylium catalyst
Hussein,Huynh,Hommelsheim,Koenigs,Nguyen
supporting information, p. 12970 - 12973 (2018/11/23)
The retro-Claisen reaction is frequently used in organic synthesis to access ester derivatives from 1,3-dicarbonyl precursors. The C-C bond cleavage in this reaction is usually promoted by a number of transition-metal Lewis acid catalysts or organic Br?nsted acids/bases. Herein we report a new convenient and efficient method utilizing the tropylium ion as a mild and environmentally friendly organocatalyst to mediate retro-Claisen-type reactions. Using this method, a range of synthetically valuable substances can be accessed via solvolysis of 1,3-dicarbonyl compounds.
"release and catch" catalysis by tungstate species for the oxidative cleavage of olefins
Yoshimura, Yu,Ogasawara, Yoshiyuki,Suzuki, Kosuke,Yamaguchi, Kazuya,Mizuno, Noritaka
, p. 1662 - 1670 (2017/07/22)
The oxidative cleavage of olefins produces valuable carbonyl compounds, and thus, the development of green catalytic methods using H2O2 as an oxidant is highly desired. In this work, we have successfully developed an efficient catalytic system for the oxidative cleavage of olefins and related compounds using H2O2. In the presence of tungstate species supported on zinc-modified tin dioxide (W/Zn-SnO2), the oxidative cleavage of 1-methyl-1-cyclohexene proceeds efficiently through multistep reaction pathways involving oxygenation, hydrolysis, perhydrolysis, and isomerization reactions. In this reaction system, active peroxotungstate species, generated by the reaction of the supported tungstate species with H2O2, are released into the solution during the course of the reaction. At the end of the reaction (after the complete consumption of H2O2), the released tungstate species are re-captured by the support. The W/Zn-SnO2 catalyst can be reused at least nine times for the oxidative cleavage of 1-methyl-1-cyclohexene without loss of catalytic performance and can be applied to the oxidation of various other substrate molecules.
