591-31-1Relevant academic research and scientific papers
Nitrosoarene-Catalyzed HFIP-Assisted Transformation of Arylmethyl Halides to Aromatic Carbonyls under Aerobic Conditions
Pradhan, Suman,Sharma, Vishali,Chatterjee, Indranil
supporting information, p. 6148 - 6152 (2021/08/03)
A rare metal-free nucleophilic nitrosoarene catalysis accompanied by highly hydrogen-bond-donor (HBD) solvent, 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP), organocatalytically converts arylmethyl halides to aromatic carbonyls. This protocol offers an effective means to access a diverse array of aromatic carbonyls with good chemoselectivity under mild reaction conditions. The activation of arylmethyl halides by HFIP to generate stable carbocation and autoxidation of in situ generated hydroxylamine to nitrosoarene in the presence of atmospheric O2 are the keys to success.
Zirconium-based metal-organic framework as an efficiently heterogeneous photocatalyst for oxidation of benzyl halides to aldehydes
Xue, Ping,Huang, Jiming,Lin, Liguang,Li, Rong,Tang, Mi,Wang, Zhengbang
, (2021/04/12)
The development of efficient heterogeneous catalysts for fine chemical synthesis is critical for practical applications. Herein, for the first time, the zirconium-based metal-organic framework (UiO-66-NH2) is applied as an efficiently heterogeneous photocatalyst for conversion of benzyl halides to corresponding aldehydes with high selectivity (about 80 %) and conversion (up to 99 %) in the presence of oxygen and DMF as solvent. Through a series of experiments and analysis, the reaction mechanism is proposed to involve nucleophilic attack of the N-oxide. This study provides a general, environmental and high selective method to prepare benzaldehydes and broadens the application fields of UiO-66-NH2.
Synthesis of new Zn (II) complexes for photo decomposition of organic dye pollutants, industrial wastewater and photo-oxidation of methyl arenes under visible-light
Ahemed, Jakeer,Bhongiri, Yadagiri,Chetti, Prabhakar,Gade, Ramesh,Kore, Ranjith,Pasha, Jakeer,Pola, Someshwar,Rao D, Venkateshwar
, (2021/07/28)
Synthesis of new Schiff's base Zn-complexes for photo-oxidation of methyl arenes and xylenes are reported under visible light irradiation conditions. All the synthesized new ligands and Zn-complexes are thoroughly characterized with various spectral analyses and confirmed as 1:1 ratio of Zn and ligand with distorted octahedral structure. The bandgap energies of the ligands are higher than its Zn-complexes. These synthesized new Zn(II) complexes are used for the photo-fragmentation of organic dye pollutants, photodegradation of food industrial wastewater and oxidation of methyl arenes which are converted into its respective aldehydes with moderate yields under visible light irradiation. The photooxidation reaction dependency on the intensity of the visible light was also studied. With the increase in the dosage of photocatalyst, the methyl groups are oxidized to get aldehydes and mono acid products, which are also identified from LC-MS data. Finally, [Zn(PPMHT)Cl] is with better efficiency than [Zn(PTHMT)Cl] and [Zn(MIMHPT)Cl] for oxidation of methyl arenes is reported under visible-light-driven conditions.
Selective Electrochemical Oxygenation of Alkylarenes to Carbonyls
Li, Xue,Bai, Fang,Liu, Chaogan,Ma, Xiaowei,Gu, Chengzhi,Dai, Bin
supporting information, p. 7445 - 7449 (2021/10/02)
An efficient electrochemical method for benzylic C(sp3)-H bond oxidation has been developed. A variety of methylarenes, methylheteroarenes, and benzylic (hetero)methylenes could be converted into the desired aryl aldehydes and aryl ketones in moderate to excellent yields in an undivided cell, using O2 as the oxygen source and lutidinium perchlorate as an electrolyte. On the basis of cyclic voltammetry studies, 18O labeling experiments, and radical trapping experiments, a possible single-electron transfer mechanism has been proposed for the electrooxidation reaction.
Xylochemical synthesis and biological evaluation of shancigusin c and bletistrin g
Efferth, Thomas,Geske, Leander,Kauhl, Ulrich,Opatz, Till,Saeed, Mohamed E. M.,Schüffler, Anja,Thines, Eckhard
, (2021/06/16)
The biological activities of shancigusin C (1) and bletistrin G (2), natural products isolated from orchids, are reported along with their first total syntheses. The total synthesis of shancigusin C (1) was conducted by employing the Perkin reaction to forge the central stilbene core, whereas the synthesis of bletistrin G (2) was achieved by the Wittig olefination followed by several regiose-lective aromatic substitution reactions. Both syntheses were completed by applying only renewable starting materials according to the principles of xylochemistry. The cytotoxic properties of shancigusin C (1) and bletistrin G (2) against tumor cells suggest suitability as a starting point for further structural variation.
Molecular iodine mediated oxidative cleavage of the C-N bond of aryl and heteroaryl (dimethylamino)methyl groups into aldehydes
Mandrekar, Ketan S.,Tilve, Santosh G.
supporting information, p. 4152 - 4155 (2021/03/15)
The oxidative cleavage of the C-N bond of aryl and heteroaryl (dimethylamino)methyl groups is achieved by employing molecular iodine as a mild oxidizing agent under ambient conditions in the presence of a mild base. The important reaction of C3 formylation of free NH and substituted indoles containing various substituents is accomplished from the corresponding Mannich bases. This methodology can also be extended for the synthesis of aryl and other heteroaryl aldehydes and ketones. Furthermore, the usefulness of the method is successfully demonstrated on a gram scale.
C70Fullerene Catalyzed Photoinduced Aerobic Oxidation of Benzylamines to Imines and Aldehydes
Kumar, Inder,Kumar, Rakesh,Gupta, Shiv Shankar,Sharma, Upendra
supporting information, p. 6449 - 6457 (2021/05/29)
C70 fullerene catalyzed photoinduced oxidation of benzylic amines at ambient conditions has been explored here. The developed strategy's main feature includes the additive/oxidant-free conversion of benzylic amine to corresponding imine and aldehydes. The reaction manifests broad substrate scope with excellent function group leniency and is applicable up to the gram scale. Further, symmetrical secondary amines can also be synthesized from benzylic amine in a one-pot two-step process. Various experiments and density functional theory studies revealed that the current reaction involves the generation of reactive oxygen species, single electron transfer reaction, and benzyl radical formation as key steps under photocatalytic conditions.
One-Pot Direct Oxidation of Primary Amines to Carboxylic Acids through Tandem ortho-Naphthoquinone-Catalyzed and TBHP-Promoted Oxidation Sequence
Kim, Hun Young,Oh, Kyungsoo,Si, Tengda
supporting information, p. 18150 - 18155 (2021/12/09)
Biomimetic oxidation of primary amines to carboxylic acids has been developed where the copper-containing amine oxidase (CuAO)-like o-NQ-catalyzed aerobic oxidation was combined with the aldehyde dehydrogenase (ALDH)-like TBHP-mediated imine oxidation protocol. Notably, the current tandem oxidation strategy provides a new mechanistic insight into the imine intermediate and the seemingly simple TBHP-mediated oxidation pathways of imines. The developed metal-free amine oxidation protocol allows the use of molecular oxygen and TBHP, safe forms of oxidant that may appeal to the industrial application.
Fe(III) superoxide radicals in halloysite nanotubes for visible-light-assisted benzyl alcohol oxidation and oxidative C[sbnd]C coupling of 2-naphthol
Bania, Kusum K.,Baruah, Manash J.,Bora, Tonmoy J.,Dutta, Rupjyoti,Guha, Ankur Kanti,Roy, Subhasish
, (2021/09/20)
Selective oxidation of benzyl alcohols to aldehydes and 2-naphthol to BINOL was achieved by activation of molecular oxygen (O2) and hydrogen peroxide (H2O2) over an iron-oxide catalyst embedded in halloysite nanotube. Electron spin resonance spectroscopy (ESR), Raman and in situ FTIR spectroscopic analysis provided direct evidence for the involvement of superoxide radical bound FeIII species in the oxidation reaction. Both the analysis suggested the end-on binding of superoxide radical with FeIII-centre. The stability of such radical bound FeIII-species in halloysite nanotube was analyzed through density functional theory (DFT) calculations. Results suggested that end-on (η1) binding was favourable by 13.5 kcal/ mol than the side-on (η2) binding mode. The formation of such reactive species was believed to play the crucial role in bringing the high selectivity in the catalytic oxidation of benzyl alcohol and oxidative C[sbnd]C coupling of 2-naphthol. UV–Vis spectroscopic studies on the oxidation of benzyl alcohol suggested for the initial adsorption of substrate molecule on the catalyst surface followed by its interaction with FeIII -superoxide/hydroperoxide species generated upon photoirradiation with visible light in presence of O2. The presence of a suitable band gap ～2.14 eV enabled the catalyst to catalyze the reaction under visible light irradiation. Both the reactions (benzyl alcohol and 2-naphthol oxidation) were tested in presence of both O2 and H2O2 as oxidants at ambient temperature. The influence of different parameters like rate of oxygen flow, amount of peroxide, nature of solvent, and catalyst amount on the conversion and selectivity of the reactions were studied to understand their role in the catalytic reactions. Successful oxidation of 2-naphthol with H2O2 as oxidant was a real success to overcome the limitations associated with this reaction using H2O2 as oxidant.
V2O5@TiO2 Catalyzed Green and Selective Oxidation of Alcohols, Alkylbenzenes and Styrenes to Carbonyls
Upadhyay, Rahul,Kumar, Shashi,Maurya, Sushil K.
, p. 3594 - 3600 (2021/07/02)
The versatile application of different functional groups such as alcohols (1° and 2°), alkyl arenes, and (aryl)olefins to construct carbon-oxygen bond via oxidation is an area of intense research. Here, we report a reusable heterogeneous V2O5@TiO2 catalyzed selective oxidation of various functionalities utilizing different mild and eco-compatible oxidants under greener reaction conditions. The method was successfully applied for the alcohol oxidation, oxidative scission of styrenes, and benzylic C?H oxidation to their corresponding aldehydes and ketones. The utilization of mild and eco-friendly oxidizing reagents such as K2S2O8, H2O2 (30 % aq.), TBHP (70 % aq.), broad substrate scope, gram-scale synthesis, and catalyst recyclability are notable features of the developed protocol.
