586-76-5Relevant articles and documents
Selective conversion of aldehydes to carboxylic acids by hemoglobin and air
Hajimohammadi, Mahdi,Verjani, Maryam Khalaji,Ghasemi, Hoda,Safari, Nasser,Kn?r, Günther
, p. 679 - 685 (2018)
A new green, environmentally friendly and economically feasible method for the oxygenation of benzaldehyde, cinnamaldehyde, 4-chlorobenzaldehyde and 4-bromobenzaldehyde to the corresponding carboxylic acids using air in the presence of hemoglobin as a water-soluble catalyst in aqueous media at room temperature is illustrated. The resulting products were obtained with (77-100%) conversion and 100% selectivity within a reasonable amount of time. In addition, the first direct characterization of a high-valent iron intermediate (HbFeIV+ =O) measured using Mass Spectroscopy (MS) and UV-vis spectroscopy proved that the major route for oxidation of aldehydes is (HbFeIV+ =O) production.
Mesoporous silica-supported Pd catalysts: An investigation into structure, activity, leaching and heterogeneity
Webb, Jonathan D.,MacQuarrie, Stephanie,McEleney, Kevin,Crudden, Cathleen M.
, p. 97 - 109 (2007)
Mesoporous silica functionalized by mercaptopropyl trimethoxysilane can be loaded with palladium and the resulting material used as a catalyst for a variety of coupling reactions. The ordered silicate reacts with levels of Pd leaching in the low ppm to ppb range. The catalyst can be re-used multiple times with only moderate loss of activity or structure, depending on the method of incorporation of the thiol. A grafting approach gives a significantly more stable material which is likely insulated from attack by the aqueous base, while incorporation of the thiol by co-condensation gives a material with minimal stability under the reaction conditions. Several heterogeneity tests are performed on the catalyst including three-phase tests and poisoning studies. These indicate that the effective heterogeneity depends strongly on the solvent employed and the reaction conditions. Under non-aerobic conditions with a controlled ratio of sulfur ligand to palladium, low levels of reaction due to homogeneous species are observed, but as the organic content of the solvent is increased, more reaction on an immobilized reagent (as judged through the three-phase test) is observed. In addition, these studies highlight the constraints within which the three-phase test can be an accurate assessment of heterogeneity.
Experimental and theoretical studies of (4?+?1) annulations between α-oxoketenes and stable phosphorous, nitrogen, or sulfur ylides
Pierrot, David,Rajzmann, Michel,Carissan, Yannick,Rodriguez, Jean,Bonne, Damien,Coquerel, Yoann
, (2019)
α-Oxoketenes generated in situ by a microwave-assisted Wolff rearrangement at 170°C were found to react with stabilized sulfur ylides in (4?+?1) annulation processes to afford functionalized 3-hydroxyfurans. Theoretical mechanistic investigations revealed that the reaction proceeds in two steps via a short-lived betaine intermediate, a general feature of the reactions of α-oxoketenes with stable phosphorous, nitrogen, and sulfur ylides.
Synthesis, catalytic activity, and leaching studies of a heterogeneous Pd-catalyst including an immobilized bis(oxazoline) ligand
Gruber-Woelfler,Radaschitz,Feenstra,Haas,Khinast
, p. 30 - 40 (2012)
The synthesis and characterization of a novel catalytic system including Pd(OAc)2 attached to a bis(oxazoline) (=BOX) ligand that is covalently bonded to 3-mercaptopropyl-functionalized silica gel is presented. The catalyst was tested for Suzuki-Miyaura reactions of different aryl halides with phenylboronic acid. The heterogeneity of the catalytic system was investigated using different approaches, indicating that there is virtually no Pd leaching into the reaction solution under the applied reaction conditions. Furthermore, our results show that the catalytic system can be reused multiple times without significant loss of stability or structure.
Transformation of Thioacids into Carboxylic Acids via a Visible-Light-Promoted Atomic Substitution Process
Fu, Qiang,Liang, Fu-Shun,Lou, Da-Wei,Pan, Gao-Feng,Wang, Rui,Wu, Min,Xie, Kai-Jun
supporting information, p. 2020 - 2024 (2022/03/31)
A visible-light-promoted atomic substitution reaction for transforming thiocacids into carboxylic acids with dimethyl sulfoxide (DMSO) as the oxygen source has been developed, affording various alkyl and aryl carboxylic acids in over 90% yields. The atomic substitution process proceeds smoothly through the photochemical reactivity of the formed hydrogen-bonding adduct between thioacids and DMSO. A DMSO-involved proton-coupled electron transfer (PCET) and the simultaneous generation of thiyl and hydroxyl radicals are proposed to be key steps for realizing the transformation.
Aerobic oxidation of aldehydes to carboxylic acids catalyzed by recyclable ag/c3 n4 catalyst
Wu, Chaolong,Yao, Xiaoquan,Yu, Min,Zhou, Li,Zhu, Li
, p. 167 - 175 (2021/03/19)
The oxidation of aldehydes is an efficient methodology for the synthesis of carboxylic acids. Herein we hope to report a simple, efficient and recyclable protocol for aerobic oxidation of aldehydes to carboxylic acid by using C3N4 supported silver nanoparticles (Ag/C3N4) as a catalyst in aqueous solution under mild conditions. Under standard conditions, the corresponding carboxylic acids can be obtained in good to excellent yields. In addition, Ag/C3N4 is convenient for recovery and could be reused three times with satisfactory yields.
Isotruxene-based porous polymers as efficient and recyclable photocatalysts for visible-light induced metal-free oxidative organic transformations
Zhang, Haowen,Zhang, Xiao,Zheng, Ying,Zhou, Cen
supporting information, p. 8878 - 8885 (2021/11/27)
Two new isotruxene-based porous polymers were prepared and demonstrated to be highly efficient, metal-free heterogeneous photocatalysts for oxidative transformations using air as the mild oxidant under visible-light irradiation. Both catalysts show excellent recyclability. In addition, the reactions can be performed in water, further indicating the greenness of this method. This journal is
