446-51-5Relevant articles and documents
Pt nanoparticles entrapped in mesoporous metal-organic frameworks MIL-101 as an efficient catalyst for liquid-phase hydrogenation of benzaldehydes and nitrobenzenes
Pan, Huiyan,Li, Xiaohong,Yu, Yin,Li, Junrui,Hu, Jun,Guan, Yejun,Wu, Peng
, p. 1 - 9 (2015)
Metal organic-framework MIL-101 and inorganic mesoporous composites Al2O3@SBA-15 supported Pt catalysts, Pt/MIL-101 and Pt/Al2O3@SBA-15 catalysts, were prepared and characterized by means of X-ray diffraction (XRD), N2 adsorption-desorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), CO chemisorption and thermo-gravimetric (TG) analysis. Pt nanoparticles were highly dispersed on both supports. In liquid-phase hydrogenation of nitrobenzene, benzaldehyde and their derivatives, the Pt/MIL-101 catalyst was superior to the Pt/Al2O3@SBA-15 catalyst in water. For liquid-phase hydrogenation of nitrobenzene with the Pt/MIL-101 catalyst, owing to high solubility of nitrobenzene in ethanol, the reaction in ethanol went much faster than that in water, furnishing a turnover frequency (TOF) in ethanol up to 18,053 h-1, almost triple of that obtained in water under similar conditions. The highest TOF of 25,438 h-1 was obtained in ethanol for hydrogenation of 3-chloro-nitrobenzene with the Pt/MIL-101 catalyst. As for hydrogenation of benzaldehyde series, 2-fluoro-benzaldehyde and 3-fluoro-benzaldehyde gave the highest TOFs of 5146 h-1 and 3165 h-1 in water with the Pt/MIL-101 and Pt/Al2O3@SBA-15 catalysts, respectively. We deduce that surface property of MIL-101 with high hydrophobicity is helpful to enrich reactants around the Pt/MIL-101 catalyst in water, where nitrobenzene or benzaldehyde and its derivatives have a limited solubility, so that high catalytic performance was achieved with the Pt/MIL-101 catalyst in water. Of particular note is that the Pt/MIL-101 catalyst can be reused at least four times without loss in activity or selectivity.
Reaction of Diisobutylaluminum Borohydride, a Binary Hydride, with Selected Organic Compounds Containing Representative Functional Groups
Amberchan, Gabriella,Snelling, Rachel A.,Moya, Enrique,Landi, Madison,Lutz, Kyle,Gatihi, Roxanne,Singaram, Bakthan
supporting information, p. 6207 - 6227 (2021/05/06)
The binary hydride, diisobutylaluminum borohydride [(iBu)2AlBH4], synthesized from diisobutylaluminum hydride (DIBAL) and borane dimethyl sulfide (BMS) has shown great potential in reducing a variety of organic functional groups. This unique binary hydride, (iBu)2AlBH4, is readily synthesized, versatile, and simple to use. Aldehydes, ketones, esters, and epoxides are reduced very fast to the corresponding alcohols in essentially quantitative yields. This binary hydride can reduce tertiary amides rapidly to the corresponding amines at 25 °C in an efficient manner. Furthermore, nitriles are converted into the corresponding amines in essentially quantitative yields. These reactions occur under ambient conditions and are completed in an hour or less. The reduction products are isolated through a simple acid-base extraction and without the use of column chromatography. Further investigation showed that (iBu)2AlBH4 has the potential to be a selective hydride donor as shown through a series of competitive reactions. Similarities and differences between (iBu)2AlBH4, DIBAL, and BMS are discussed.
Generation of Oxidoreductases with Dual Alcohol Dehydrogenase and Amine Dehydrogenase Activity
Tseliou, Vasilis,Schilder, Don,Masman, Marcelo F.,Knaus, Tanja,Mutti, Francesco G.
supporting information, p. 3315 - 3325 (2020/12/11)
The l-lysine-?-dehydrogenase (LysEDH) from Geobacillus stearothermophilus naturally catalyzes the oxidative deamination of the ?-amino group of l-lysine. We previously engineered this enzyme to create amine dehydrogenase (AmDH) variants that possess a new hydrophobic cavity in their active site such that aromatic ketones can bind and be converted into α-chiral amines with excellent enantioselectivity. We also recently observed that LysEDH was capable of reducing aromatic aldehydes into primary alcohols. Herein, we harnessed the promiscuous alcohol dehydrogenase (ADH) activity of LysEDH to create new variants that exhibited enhanced catalytic activity for the reduction of substituted benzaldehydes and arylaliphatic aldehydes to primary alcohols. Notably, these novel engineered dehydrogenases also catalyzed the reductive amination of a variety of aldehydes and ketones with excellent enantioselectivity, thus exhibiting a dual AmDH/ADH activity. We envisioned that the catalytic bi-functionality of these enzymes could be applied for the direct conversion of alcohols into amines. As a proof-of-principle, we performed an unprecedented one-pot “hydrogen-borrowing” cascade to convert benzyl alcohol to benzylamine using a single enzyme. Conducting the same biocatalytic cascade in the presence of cofactor recycling enzymes (i.e., NADH-oxidase and formate dehydrogenase) increased the reaction yields. In summary, this work provides the first examples of enzymes showing “alcohol aminase” activity.
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).
