92-82-0Relevant articles and documents
Enthalpies of combustion of phenazine N-oxide, phenazine, benzofuroxan, and benzofurazan: the dissociation enthalpies of the (N-O) bonds
Leitao, M. Luisa P.,Pilcher, G.,Acree, W. E.,Zvaigzne, Anita I.,Tucker, Sheryl A.,et al.
, p. 923 - 928 (1990)
The standard (p0 = 0.1 MPa) molar enthalpies of combustion at 298.15 K were measured by static-bomb calorimetry and the standard molar enthalpies of sublimation at 298.15 K were measured by microcalorimetry for phenazine, benzofurazon, and their corresponding N-oxides: From the standard molar enthalpies of formation of the gaseous compounds, the molar dissociation enthalpies of the (N-O) bonds were derived: D(N-O)/(kJ*mol-1): phenazine N-oxide, 280.7 +/- 5.6; benzofuroxan, 250.9 +/- 3.0.
Solvent Dependent Bergman Cyclization of 2,3-Diethynylquinoxaline
Kim, Chang-Sik,Russell, K. C.
, p. 3835 - 3838 (1999)
Kinetics of thermocyclization of 2,3-diethynylquinoxaline have been studied in various solvents. The cyclization rates observed were surprisingly solvent dependent. The half-lives varied from 361 in CH3CN to 16 min in THF. The half-life data show a good correlation with the solvents' spectroscopic ET(30) values and dielectric constants.
Enhanced catalytic activity in organic solvents using molecularly dispersed haemoglobin-polymer surfactant constructs
Zhang, Yixiong,Patil, Avinash J.,Perriman, Adam W.,Mann, Stephen
, p. 9561 - 9563 (2013)
The surface of haemoglobin (Hb) is chemically modified to produce molecular dispersions of discrete core-shell Hb-polymer surfactant bionanoconjugates in water and organic solvents. The hybrid nanoconstructs exhibit peroxidase-like catalytic activity with enhanced turnover rates compared with native Hb in water. The Royal Society of Chemistry 2013.
One-pot production of phenazine from lignin-derived catechol
He, Zhimin,Qi, Wei,Ren, Tianyu,Yan, Ning
, p. 1224 - 1230 (2022/02/17)
Upgrading lignin-derived monomeric products is crucial in bio-refineries to effectively utilize lignin. Herein, we report a simple strategy to convert catechol to phenazine, a useful N-heterocycle three-aromatic-ring compound, whose current synthetic procedure is complex via a petroleum-derived feedstock. The reaction uses catechol as the sole carbon source and aqueous ammonia as reaction media and a nitrogen source. Without additional solvents, phenazine was obtained in 67% yield in the form of high purity crystals (>97%) over a Pd/C catalyst after a one-pot-two-stage reaction. When cyclohexane was used as a co-solvent in the first step, a higher yield (81%) and purity (>99%) were achieved. Mechanistic investigations involving control experiments and an isotope labeling study reveal that hydrogenation, amination, coupling and dehydrogenation reactions are the key steps leading to phenazine formation. The conversion of other lignin-derived catechols highlights that the protocol is extendable to produce substituted phenazines.
An umpolung strategy for rapid access to thermally activated delayed fluorescence (TADF) materials based on phenazine
Cheng, Hu,Guo, Qiang,Lan, Jingbo,Ran, Chunhao,Wu, Di,Zhang, Huaxing
supporting information, p. 1581 - 1584 (2022/02/10)
Herein, Ag(I)-promoted regioselective intramolecular radical nucleophilic addition/rearrangement of 2-aryl diazaboroles has been accomplished for the first time to construct phenazine structures. This protocol is an umpolung strategy based on the classical electrophilic mechanism, and therefore, a reversed regioselectivity was observed, which provides an opportunity to prepare sterically hindered phenazines. The resulting thermally activated delayed fluorescence (TADF) materials based on phenazine exhibit emission bands from green to red with high quantum yields and moderate fluorescence lifetimes as solid films.
The silver-mediated annulation of arylcarbamic acids and nitrosoarenes toward phenazines
Chen, Fan,Cheng, Jiang,Qian, Peng-Cheng,Wang, Lu
, (2021/12/17)
A silver-mediated annulation between arylcarbamic acids and nitrosoarenes was developed, leading to phenazines in moderate to good yields with complexity and diversity. This procedure proceeded with the sequential ortho[sbnd] C[sbnd]H functionalization of arylcarbamic acids, insertion to nitroso group and decarboxylative annulation.
Decarboxylation of Aromatic Carboxylic Acids by the Prenylated-FMN-dependent Enzyme Phenazine-1-carboxylic Acid Decarboxylase
Datar, Prathamesh M.,Marsh, E. Neil G.
, p. 11723 - 11732 (2021/09/28)
Phenazine-1-carboxylic acid decarboxylase (PhdA) is a member of the expanding class of prenylated-FMN-dependent (prFMN) decarboxylase enzymes. These enzymes have attracted interest for their ability to catalyze (de)carboxylation reactions on aromatic rings and conjugated double bonds. Here we describe a method to reconstitute PhdA with prFMN that produces an active and stable form of the holo-enzyme that does not require prereduction with dithionite for activity. We establish that oxidized phenazine-1-carboxylate (PCA) is the substrate for decarboxylation, withkcat= 2.6 s-1andKM= 53 μM. PhdA also catalyzes the much slower exchange of solvent deuterium into the product, phenazine, with an apparent turnover number of 0.8 min-1. The enzyme was found to catalyze the decarboxylation of a broad range of polyaromatic carboxylic acids, including anthracene-1-carboxylic acid. Previously described prFMN-dependent aromatic (de)carboxylases have utilized electron-rich phenolic or heterocyclic molecules as substrates. PhdA extends the substrate range of prFMN-dependent (de)carboxylases to electron-poor and unfunctionalized aromatic systems, suggesting that it may prove a useful catalyst for the regioselective (de)carboxylation of otherwise unreactive aromatic molecules.
K2S2O8activation by glucose at room temperature for the synthesis and functionalization of heterocycles in water
Hunjan, Mandeep Kaur,Laha, Joydev K.
, p. 8437 - 8440 (2021/09/02)
While persulfate activation at room temperature using glucose has primarily been focused on kinetic studies of the sulfate radical anion, the utilization of this protocol in organic synthesis is rarely demonstrated. We reinvestigated selected K2S2O8-mediated known organic reactions that invariably require higher temperatures and an organic solvent. A diverse, mild functionalization and synthesis of heterocycles using the inexpensive oxidant K2S2O8 in water at room temperature is reported, demonstrating the sustainability and broad scope of the method. Unlike traditional methods used for persulfate activation, the current method uses naturally abundant glucose as a K2S2O8 activator, avoiding the use of higher temperature, UV light, transition metals or bases.
PHENAZINE-BASED COMPOUNDS AND USE THEREOF AS REDOX FLOW BATTERY ELECTROLYTE
-
Page/Page column 68, (2021/08/27)
The present invention relates to novel phenazine-based compounds of formula (l)(a) and (l)(b) and compositions comprising the same and their use as redox flow battery electrolytes.(l)(a), (l)(b)
Aerobic Dehydrogenation of N-Heterocycles with Grubbs Catalyst: Its Application to Assisted-Tandem Catalysis to Construct N-Containing Fused Heteroarenes
Kawauchi, Daichi,Noda, Kenta,Komatsu, Yoshiyuki,Yoshida, Kei,Ueda, Hirofumi,Tokuyama, Hidetoshi
, p. 15793 - 15798 (2020/10/12)
An aerobic dehydrogenation of nitrogen-containing heterocycles catalyzed by Grubbs catalyst is developed. The reaction is applicable to various nitrogen-containing heterocycles. The exceptionally high functional group compatibility of this method was confirmed by the oxidation of an unprotected dihydroindolactam V to indolactam V. Furthermore, by taking advantage of the oxygen-mediated structural change of the Grubbs catalyst, we integrated ring-closing metathesis and subsequent aerobic dehydrogenation to develop the novel assisted-tandem catalysis using molecular oxygen as a chemical trigger. The utility of the assisted-tandem catalysis was demonstrated by the concise synthesis of N-containing fused heteroarenes including a natural antibiotic, pyocyanine.
