58478-75-4Relevant academic research and scientific papers
Donor-Acceptor (Electronic) Coupling in the Precursor Complex to Organic Electron Transfer: Intermolecular and Intramolecular Self-Exchange between Phenothiazine Redox Centers
Sun, Duoli,Rosokha, Sergiy V.,Kochi, Jay K.
, p. 1388 - 1401 (2004)
Intermolecular electron transfer (ET) between the free phenothiazine donor (PH) and its cation radical (PH.+) proceeds via the [1:1] precursor complex (PH)2.+ which is transiently observed for the first time by its diagnostic (charge-resonance) absorption band in the near-IR region. Similar intervalence (optical) transitions are also observed in mixed-valence cation radicals with the generic representation: P(br)P .+, in which two phenothiazine redox centers are interlinked by p-phenylene, o-xylylene, and o-phenylene (br) bridges. Mulliken-Hush analysis of the intervalence (charge-resonance) bands afford reliable values of the electronic coupling element HIV based on the separation parameters for (P/P.+) centers estimated from some X-ray structures of the intermolecular (PH)2.+ and the intramolecular P(br)P .+ systems. The values of HIV, together with the reorganization energies λ derived from the intervalence transitions, yield activation barriers ΔGET? and first-order rate constants kET for electron-transfer based on the Marcus-Hush (two-state) formalism. Such theoretically based values of the intrinsic barrier and ET rate constants agree with the experimental activation barrier (E a) and the self-exchange rate constant (kSE) independently determined by ESR line broadening measurements. This convergence validates the use of the two-state model to adequately evaluate the critical electronic coupling elements between (P/P.+) redox centers in both (a) intermolecular ET via the precursor complex and (b) intramolecular ET within bridged mixed-valence cation radicals. Important to intermolecular ET mechanism is the intervention of the strongly coupled precursor complex since it leads to electron-transfer rates of self-exchange that are 2 orders of magnitude faster (and activation barrier that is substantially lower) than otherwise predicted solely on the basis of Marcus reorganization energy.
Synthesis and properties of phenothiazine derivatives. 2. Spectral (ESR and IR) characteristics of the radical-cations of the phenothiazine N-derivatives
Tomilin,Shchegolikhin,Sanaeva,Klyakin,Ryabkina,Konovalova
, p. 1097 - 1102 (2000)
The temperature dependence of the ESR spectra of the radical-cations of the N-derivatives of phenothiazine were studied in the range of 200-393 K (o-xylene). It was established that at temperatures of 323-333 K the nature of the HFS varies from doublet to quartet with approximate intensity ratios of 1:2:2:1, and this transformation is irreversible. A hypothesis explaining the results is proposed. IR spectroscopy was used to confirm the proposed mechanism of localization of the unpaired electron.
Transition-Metal-Free and Base-Promoted Carbon-Heteroatom Bond Formation via C-N Cleavage of Benzyl Ammonium Salts
Liu, Long,Tang, Yuanyuan,Wang, Kunyu,Huang, Tianzeng,Chen, Tieqiao
, p. 4159 - 4170 (2021/03/09)
A facile and general method for constructing carbon-heteroatom (C-P, C-O, C-S, and C-N) bonds via C-N cleavage of benzyl ammonium salts under transition-metal-free conditions was reported. The combination of t-BuOK and 18-crown-6 enabled a wide range of substituted benzyl ammonium salts to couple readily with different kinds of heteroatom nucleophiles, i.e. hydrogen phosphoryl compounds, alcohols, thiols, and amines. Good functional group tolerance was demonstrated. The scale-up reaction and one-pot synthesis were also successfully performed.
Non-directed copper-catalyzed regioselective C-H sulfonylation of phenothiazines
Liu, Caiyan,Shen, Yongli,Yuan, Kedong
supporting information, p. 5009 - 5013 (2019/06/03)
We develop a simple and general method for sulfonylation of phenothiazines under Cu(i) catalysis. The broad scope of aryl/alkyl sulfonyl chlorides was applicable to produce C3 sulfonylation products of phenothiazines in moderate to good yields. The further transformation of the sulfonylation products was successful, which afforded valuable polyheterocycles.
Base Catalysis Enables Access to α,α-Difluoroalkylthioethers
Orsi, Douglas L.,Easley, Brandon J.,Lick, Ashley M.,Altman, Ryan A.
supporting information, p. 1570 - 1573 (2017/04/13)
A nucleophilic addition reaction of aryl thiols to readily available β,β-difluorostyrenes provides α,α-difluoroalkylthioethers. The reaction proceeds through an unstable anionic intermediate, prone to eliminate fluoride and generate α-fluorovinylthioethers. However, the use of base catalysis overcomes the facile β-fluoride elimination, generating α,α-difluoroalkylthioethers in excellent yields and selectivities.
Pd-Catalyzed double N-arylation of primary amines to synthesize phenoxazines and phenothiazines
Zhang, Lu,Huang, Xin,Zhen, Shan,Zhao, Jing,Li, Heng,Yuan, Bingxin,Yang, Guanyu
, p. 6306 - 6309 (2017/08/10)
An efficient and versatile Pd-catalyzed tandem C-N bond formation between aryl halides and primary amines is developed. The transformation allows a one-pot synthesis of phenoxazine and phenothiazine derivatives with a broad range of substitution patterns from readily available precursors.
An efficient ultrasound-assisted synthesis of n-alkyl derivatives of carbazole, indole, and phenothiazine
Zhao, Sanhu,Kang, Jin,Du, Yuting,Kang, Jingyan,Zhao, Xiaoni,Xu, Yinfeng,Chen, Ruixi,Wang, Qianqian,Shi, Xitao
supporting information, p. 683 - 689 (2014/06/10)
Heterocyclic compounds bearing an acidic hydrogen atom attached to nitrogen such as carbazole, indole, and phenothiazine can be efficiently alkylated in DMSO or N,N-DMF under ultrasonic irradiation in the presence of potassium hydroxide as a base. In almost all cases, a dramatic reduction of the reaction time results and a clear yield increase accompanied by an improved quality of the products occurs.
POLYMERIZATION INHIBITOR COMPOSITION AND METHOD OF INHIBITING POLYMERIZATION OF DISTILLABLE MONOMERS
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Page/Page column 10, (2011/12/13)
The present invention relates to a polymerization inhibitor composition and a method of inhibiting polymerization of distillable monomers in liquid and evaporated/condensed phases with the polymerization inhibitor composition. The polymerization inhibitor composition is useful for inhibiting polymerization of the distillable monomers during manufacture, purification (e.g., distillation), handling, and storage thereof.
The role of phase transfer catalysis in the microwave-assisted N-benzylation of amides, imides and N-heterocycles
Greiner, Istvan,Sypaseuth, Fanni Daruny,Gruen, Alajos,Karsai, Eva,Keglevich, Gyoergy
experimental part, p. 529 - 534 (2010/04/23)
The effect of triethylbenzylammonium chloride (TEBAC) was studied on the outcome of the microwaveassisted solid-liquid phase N-alkylation of amides, imides and N-heterocycles using benzyl halides and K2CO3. It was found that while the benzylation of amides may be somewhat promoted by the presence of TEBAC, succinimide and benzimidazole are so reactive that there is no need to use the catalyst. At the same time, the outcome of the benzylation of phenothiazine may be significantly influenced by the presence or absence of TEBAC in respect of N-versus C-alkylation.
Palladium-catalyzed three-component approach to promazine with formation of one carbon-sulfur and two carbon-nitrogen bonds
Dahl, Troels,Tornoe, Christian W.,Bang-Andersen, Benny,Nielsen, Poul,Jorgensen, Morten
supporting information; scheme or table, p. 1726 - 1728 (2009/02/06)
(Chemical Presented) Zip it up! The use of a Pd/dppf catalyst gives access to the tricyclic phenothiazine scaffold starting from 1-bromo-2-iodobenzenes, aliphatic or aromatic amines, and 2-bromothiophenols in a single reaction flask (see scheme; dppf=1,1′-bis(diphenylphosphanyl) ferrocene; dba=dibenzylidineacetone). This transformation involves thioether formation and subsequent intermolecular and intramolecular aryl amination reactions. The reaction occurs in good overall yield and selectivity.
