22711-20-2Relevant academic research and scientific papers
Vibrational assignment of para-dimethylaminobenzil and its 18O-substituted derivative
Radomirska, Valentina,Kolev, Tsonko,Juchnovski, Ivan
, p. 409 - 412 (1997)
The results of FTIR and Raman spectroscopic investigations into para-dimethylaminobenzil and its 18O-substituted derivative are presented and a preliminary assignment proposed on the basis of ab initio quantum chemical calculations.
Magnesium Aldimines Prepared by Addition of Organomagnesium Halides to 2,4,6-Trichlorophenyl Isocyanide: Synthesis of 1,2-Dicarbonyl Derivatives
Schw?rzer, Kuno,Bellan, Andreas,Z?schg, Maximilian,Karaghiosoff, Konstantin,Knochel, Paul
supporting information, p. 9415 - 9418 (2019/05/10)
The selective addition of organomagnesium reagents to 2,4,6-trichlorophenyl isocyanide leading to magnesiated aldimines is reported. These aldimines react with Weinreb amides, ketones, or carbonates to provide the corresponding carbonyl derivatives after acidic cleavage. This allows for an efficient synthesis of 1,2-dicarbonyl compounds and α-hydroxy ketones.
Co3O4-decorated carbon nanotubes as a novel efficient catalyst in the selective oxidation of benzoins
Safari, Javad,Mansouri Kafroudi, Zahra,Zarnegar, Zohre
, p. 958 - 963 (2014/08/18)
An efficient and facile air oxidation of benzoins in the presence of the heterogeneous catalyst, Co3O4-CNTs nanocomposite, has been developed. It thus constitutes a very simple, clean, economical and selective method for the aerobic preparation of benzils from the corresponding benzoins. The catalyst can be re-used a number of times without losing its catalytic activity to a greater extent.
Red-emitting dyes with photophysical and photochemical properties controlled by pH
Novakova, Veronika,Miletin, Miroslav,Kopecky, Kamil,Zimcik, Petr
scheme or table, p. 14273 - 14282 (2012/01/06)
New unsymmetrical zinc azaphthalocyanines, bearing one substituted aniline as a peripheral substituent, were prepared by using a statistical condensation approach. Both fluorescence and singlet oxygen quantum yields were extremely low in DMF (φFΔF=0. 22-0.29, φΔ=0.40-0.59, respectively). This behavior was attributed to the deactivation of excited states by intramolecular charge transfer from a donor site (aniline), which was blocked after protonation in acidic media. In the protonated form, all of the compounds efficiently emitted light with λem in the region of 662-675 nm. The investigated compounds were anchored to dioleoylphosphatidylcholine (DOPC) unilamellar vesicles and showed response to buffer pH. They were highly fluorescent at low pH values and almost nonfluorescent in neutral solutions. The pKa values were determined in DOPC vesicles and ranged between 2.2 and 4.2.
Influence of protonation of peripheral substituents on photophysical and photochemical properties of tetrapyrazinoporphyrazines
Novakova, Veronika,M?rkved, Eva H.,Miletin, Miroslav,Zimcik, Petr
scheme or table, p. 582 - 591 (2011/10/03)
Octasubstituted zinc tetrapyrazinoporphyrazines with four N,N-dimethylaminophenyls and four phenyl or pyridin-3-yl substituents were synthesized and fully characterized. Their fluorescence quantum yields in DMF or pyridine were very low, almost undetectable, as a consequence of ultrafast intramolecular charge transfer. Titration of their DMF solutions with sulfuric acid led to increase of the fluorescence quantum yields by two orders of magnitude when the full protonation of peripheral substituents was achieved. Intramolecular charge transfer is no longer a favorable way of excited-state relaxation at full protonation of N,N-dimethylaminophenyl substituents because of loss of donor centers (free electron pair on its nitrogen). Similarly, singlet oxygen quantum yields also increased by two orders of magnitude when sulfuric acid was added to tetrapyrazinoporphyrazine solutions in DMF. Protonation at azomethine nitrogens of tetrapyrazinoporphyrazine macrocycle was observed at higher acid concentrations and it led to considerable decrease of fluorescence quantum yields. Octaphenyl zinc tetrapyrazinoporphyrazine and octa(pyridin-3-yl) zinc tetrapyrazinoporphyrazine were used as controls without intramolecular charge transfer. Their fluorescence and singlet oxygen quantum yields were high in DMF and decreased at higher concentrations of sulfuric acid due to protonation of azomethine nitrogens. The results suggest that the photophysical and photochemical properties of studied compounds may be controlled by changes of pH of medium.
Preparation, crystal structures, and properties of new conjugated π-electron systems with 3-guaiazulenyl and 4-(dimethylamino)phenyl groups
Takekuma, Shin-Ichi,Hori, Seiki,Minematsu, Toshie,Takekuma, Hideko
experimental part, p. 1472 - 1484 (2009/05/06)
Reaction of guaiazulene with l,2-bis[4-(dimethylamino)phenyl]-l,2- ethanediol in methanol in the presence of hydrochloric acid at 60°C for 3h gives l,l-bis[4-(dimethylamino)phenyl]-2-(3-guaiazulenyl)ethylene, in 81% yield, via pinacol rearrangement and fu
Alumina and silica oxides as catalysts for the oxidation of benzoins to benzils under solvent-free conditions
Noroozi-Pesyan,Dabbagh
, p. 1364 - 1368 (2007/10/03)
Alumina or silica gel are used as catalysts for a solvent-free oxidation of benzoins to the corresponding benzils. These catalysts are easily recovered after completion of the reactions, which are carried out either by heating in a sand bath or using micr
Electrochemical oxidation of benzoins to benzils in the presence of a catalytic amount of KI in basic media
Okimoto, Mitsuhiro,Takahashi, Yukio,Nagata, Yuji,Sasaki, Gaku,Numata, Kaori
, p. 705 - 707 (2007/10/03)
Various benzoins were transformed into the corresponding benzils via an electrochemical method. Although the strategy of oxidizing benzoins to the corresponding benzils is generally chosen depending on the nature of the aromatic moiety, the electrochemical technique reported herein allows oxidation that is widely applicable, and without the use of environmentally undesirable oxidants.
One-pot synthesis of phenytoin analogs
Mahmoodi,Emadi
, p. 377 - 382 (2007/10/03)
A series of phenytoin analogs (5,5-diphenylimidazolidine-2,4-dione or 5,5-diphenyl-hydantoin) were synthesized in 65-75% yield from the corresponding substituted benzils. The same products were also obtained directly from α-hydroxy ketones via one-pot procedure.
Iron(III)-ethylenediaminetetraacetic acid mediated aerobic oxidation of α-hydroxyketones: a simple and convenient synthesis of α-diketones
Rao, T. Venkateshwar,Dongre, Rajendra S.,Jain, Suman L.,Sain, Bir
, p. 2637 - 2642 (2007/10/03)
Iron(III)-ethylenediaminetetraacetic acid in aqueous methanol offers a simple, environmentally acceptable synthetic tool to oxidize α-hydroxyketones α-diketones with molecular oxygen, in excellent yields and under mild conditions and without any side reactions.
