38582-73-9Relevant academic research and scientific papers
Environmentally benign strategy for arylation of nitronyl nitroxide using a non-Transition metal nucleophile
Nakamura, Fumiya,Naota, Takeshi,Suzuki, Shuichi
supporting information, p. 1350 - 1354 (2020/03/13)
We have developed a method for the arylation of nitronyl nitroxide without using its transition metal complex as a nucleophile. Various nitronyl nitroxide-substituted I -electronic compounds can be obtained from the parent nitronyl nitroxide and the corresponding aryl iodides using a combination of zero-valent palladium catalysts and a 2-dicyclohexylphosphino-2′,4′,6′-Triisopropylbiphenyl ligand in the presence of sodium tert-butoxide. The utility of the method has been demonstrated by the direct synthesis of open-shell compounds with giant I -electronic systems, such as 10P.
Radical metalloids with N-heterocyclic carbene and phenanthroline ligands: Synthesis, properties, and cross-coupling reaction of [(nitronyl nitroxide)-2-ido]metal complexes with aryl halides
Yamada, Kiyomi,Zhang, Xun,Tanimoto, Ryu,Suzuki, Shuichi,Kozaki, Masatoshi,Tanaka, Rika,Okada, Keiji
, p. 1150 - 1157 (2018/07/29)
New radical metalloids, NN-AuSIMes and NNCu( bdmpphen), were prepared and their properties were investigated. They were applied to Pd(0)-mediated crosscoupling reactions with aryl halides (ArX) to produce 2-aryl (nitronyl nitroxide) s in moderate to high
Nitronyl nitroxide as a coupling partner: Pd-mediated cross-coupling of (nitronyl nitroxide-2-ido)(triphenylphosphine)gold(i) with aryl halides
Tanimoto, Ryu,Suzuki, Shuichi,Kozaki, Masatoshi,Okada, Keiji
supporting information, p. 678 - 680 (2014/05/20)
A cross-coupling reaction using nitronyl nitroxide (NN) as a coupling partner was developed: Refluxing a mixture of [AuI(NN-2-ido)(PPh3)] and aryl iodide (ArI) in THF in the presence of 10 mol% [Pd(PPh3)4] produced a cross-coupling product NN-Ar in a high yield. This method allowed the direct introduction of the NN radical onto various poly- and heterocyclic aromatic rings.
A class of novel nitronyl nitroxide labeling basic and acidic amino acids: Synthesis, application for preparing ESR optionally labeling peptides, and bioactivity investigations
Zhang, Jianwei,Zhao, Ming,Cui, Guohui,Peng, Shiqi
, p. 4019 - 4028 (2008/12/22)
Aimed at optional ESR label 2-(4′-hydroxyl)phenyl-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl was introduced into the guanido of l-Arg-OH, the ω-amino group of l-Lys-OH with methylcarboxyl as a linker, and into the β-carboxyl of l-Asp-OH and the γ-carboxyl of l-Glu-OH with ethylamino as a linker. It was explored that the synthetic 30 novel ESR labeling amino acid derivatives were stable enough to the reaction conditions of peptide synthesis. Their incorporation led to 12 novel ESR optionally labeling PAK, RGDS, RGDV, and ECG. A series of NO related chemical tests, the in vitro and in vivo assays of these peptides confirmed that this strategy was practical.
Novel 1-oxyl-2-substitutedphenyl-4,4,5,5-tetramethylimidazolines: Synthesis, selectively analgesic action, and QSAR analysis
Zhao, Ming,Li, Zheng,Peng, Li,Tang, Yu-Rong,Wang, Chao,Zhang, Ziding,Peng, Shiqi
, p. 2815 - 2826 (2007/10/03)
Based on the knowledge that imidazoline can result in analgesic action due to its selective binding with the prostacyclin receptor, 20 1-oxyl-2-substitutedphenyl-4,4,5,5-tetramethylimidazolines (3a-t) were prepared in moderate yields. At 0.13 mmol/kg dose, their in vivo analgesic activities were evaluated after the mice were administered at 30, 60, 90, and 150 min. Compared with the pain threshold (12.27 ± 9.56-17.71 ± 7.00%) of normal saline (NS) receiving mice, the pain threshold (23.42 ± 8.14% to 102.58 ± 10.66%) of 3a-t receiving mice increases significantly. Considering a prostacyclin receptor targeting analgesic agent usually had bleeding action and to appraise the bleeding risk, the in vivo tail bleeding time of 1.30 mmol/kg 3a-t receiving mice was found to be ranged from 116.3 ± 8.2 s to 120.3 ± 9.2 s, which was substantially equal to that (117.8 ± 8.4 s to 119.0 ± 8.6 s) of NS receiving mice. Based on the possibility of imidazoline acting as vasodilator, the in vitro vasorelaxations of 3a-t were tested using the rat aortic strip model. When the aortic strip contracted by noradrenaline (NE, final concentration 10-7 mol/l) was treated with 3a-t (final concentration 5 × 10-4 mol/l), only lower percentage inhibitions (6.55 ± 5.70-37.40 ± 4.07%) were recorded, implying that the vasorelaxation of 3a-t was neglectable. By selecting appropriate molecular descriptors generated from e-dragon server, the QSAR model of the analgesic activities of 3a-t was constructed using the multiple linear regression method. The established QSAR model showed reasonable accuracy and thus it is promising to be used for screening new 1-oxyl-2-substitutedphenyl-4,4,5,5-tetramethylimidazoline derivatives as analgesic agents.
Novel 2-substituted nitronyl nitroxides as free radical scavengers: Synthesis, biological evaluation and structure-activity relationship
Wu, Yihui,Bi, Lanrong,Bi, Wei,Li, Zeng,Zhao, Ming,Wang, Chao,Ju, Jingfang,Peng, Shiqi
, p. 5711 - 5720 (2007/10/03)
To develop more potent small molecules with enhanced free radical scavenger properties, we designed and synthesized a series of nitronyl nitroxide derivatives 4a-h. A lead compound 4f was discovered based on Ach-induced vascorelaxation assay. Further chemical modification based on this scaffold provided a new series of 2-substituted phenylnitronyl nitroxide derivatives 6a-s. The newly synthesized compounds 6a-s possess improved radical scavenger's activity based on PC12 cell survival assay. Compounds 6g,n,o, and s are some of the most potent compounds in terms of NO, H2O2, and OH scavenging ability. 2-Substitued phenylnitronyl nitroxides had a higher radical scavenging activity with the electron-donating group (EDG). In contrast, the introduction of electron-withdrawing group (EWG) to the aromatic ring led to a dramatic decrease in its radical scavenging activity. These results suggest that the electron-donating group (EDG) of the aromatic ring may be an important factor influencing the radical scavenging behavior of these compounds, and the potency of free radical scavenging activity largely depended on the position and electronic properties of the phenyl ring substituents. The enhanced radical scavenging capacities of the novel 2-substituted nitronyl nitroxides may be potential drug leads against the deleterious action of ROS (reactive oxygen species)/RNS (reactive nitrogen species).
TPAP/NMO system as a novel method for the synthesis of nitronyl nitroxide radicals
Gorini, Lapo,Caneschi, Andrea,Menichetti, Stefano
, p. 948 - 950 (2007/10/03)
An easy oxidation of dihydroxyimidazolidine derivatives to nitronyl nitroxide radicals (NNRs) can be achieved using the tetra-N-propylamonium perruthenate/N-methylmorpholine N-oxide (TPAP/NMO) system. The procedure offers several advantages in terms of si
Aminonitrone-N-hydroxyaminoimine tautomeric equilibrium in the series of 1-hydroxy-2-imidazolines
Popov, Sergey A.,Andreev, Rodion V.,Romanenko, Galina V.,Ovcharenko, Viktor I.,Reznikov, Vladimir A.
, p. 49 - 60 (2007/10/03)
A series of 2-substituted 1-hydroxy-4,4,5,5-tetramethyl-4,5-dihydro-1H- imidazoles have been synthesized. Various effects on the state of the aminonitrone-N-hydroxyaminoimine tautomeric equilibrium, including solvent effects and substituent effect in the 2 position of heterocycle, have been studied.
Nitronyl and imino nitroxides: Improvement of Ullman's procedure and report on a new efficient synthetic route
Hirel, Catherine,Vostrikova, Kira E.,Pecaut, Jacques,Ovcharenko, Victor I.,Rey, Paul
, p. 2007 - 2014 (2007/10/03)
The synthesis of nitronyl and imino nitroxides has been reexamined with the aim of both increasing yields and of offering opportunities for new structures. The conditions for the formation of 2,3-bis(hydroxyamino)-2,3-dimethylbutane, the key intermediate of Ullman's route, have been carefully studied, and a new procedure is proposed, which affords the free base in a very pure form and up to 60% yield. Full characterization of this intermediate including an X-ray crystal structure is presented. An alternative synthetic route through 2,3-diamino-2,3-dimethylbutane and the corresponding imidazolidines which bypasses the delicate synthesis of the bis(hydroxyamino) compound is described. It is shown that 3-chloroperbenzoic acid is an effective oxidant for the transformation of adequately substituted imidazolidines into nitronyl nitroxides, which are obtained in high yield. An illustration of the potentialities of this new route, a new nitronyl nitroxide with two ethyl substituents in positions 4 and 5 of the imidazoline ring, is reported. The scope and limitations of the two routes are discussed.
SUBSTITUENT EFFECT ON THE REACTION OF 2-(SUBSTITUTED PHENYL)-4,5-DIHYDRO-4,4,5,5-TETRAMETHYLIMIDAZOL-1-OXYL 3-OXIDES WITH NITRIC OXIDE: AN EXPERIMENTAL AND MNDO STUDY
Shimomura, Osamu,Abe, Kazuhisa,Hirota, Minoru
, p. 795 - 798 (2007/10/02)
The relative rate constants of the oxygen transfer reaction of 2-(substituted phenyl)-4,5-dihydro-4,4,5,5-tetramethylimidazol-1-oxyl 3-oxides with nitric acid have been measured by using liquid chromatography (h.p.l.c.).The Hammett ρ value (-0.37) indicates that electron-donating substituents favour the reaction.This can be explained by a mechanism which includes electron transfer to nitric oxide and can be rationalised by frontier orbital energies and electron densities on the nitroxyl oxygen calculated by semiempirical MNDO methods.
