475571-19-8Relevant articles and documents
Insights into the antiproliferative mechanism of (C^N)-chelated half-sandwich iridium complexes
Ramos, Robin,Zimbron, Jérémy M.,Thorimbert, Serge,Chamoreau, Lise-Marie,Munier, Annie,Botuha, Candice,Karaiskou, Anthi,Salmain, Michèle,Sobczak-Thépot, Jo?lle
, p. 17635 - 17641 (2020/12/30)
Transition metal-based anticancer compounds, as an alternative to platinum derivatives, are raising scientific interest as they may present distinct although poorly understood mechanisms of action. We used a structure-activity relationship-based methodology to investigate the chemical and biological features of a series of ten (C^N)-chelated half-sandwich iridiumIII complexes of the general formula [IrCp?(phox)Cl], where (phox) is a 2-phenyloxazoline ligand forming a 5-membered metallacycle. This series of compounds undergoes a fast exchange of their chlorido ligand once solubilised in DMSO. They were cytotoxic to HeLa cells with IC50 values in the micromolar range and induced a rapid activation of caspase-3, an apoptosis marker. In vitro, the oxidative power of all the complexes towards NADH was highlighted but only the complexes bearing substituents on the oxazoline ring were able to produce H2O2 at the micromolar range. However, we demonstrated using a powerful HyPer protein redox sensor-based flow cytometry assay that most complexes rapidly raised intracellular levels of H2O2. Hence, this study shows that oxidative stress can partly explain the cytotoxicity of these complexes on the HeLa cell line and gives a first entry to their mechanism of action. This journal is
Highly diastereoselective and enantioselective olefin cyclopropanation using engineered myoglobin-based catalysts
Bordeaux, Melanie,Tyagi, Vikas,Fasan, Rudi
, p. 1744 - 1748 (2015/02/19)
Using rational design, an engineered myoglobinbased catalyst capable of catalyzing the cyclopropanation of aryl-substituted olefins with catalytic proficiency (up to 46800 turnovers) and excellent diastereo- and enantioselectivity (98-99.9%) was developed. This transformation could be carried out in the presence of up to 20 gL-1 olefin substrate with no loss in diastereo- and/or enantioselectivity. Mutagenesis and mechanistic studies support a cyclopropanation mechanism mediated by an electrophilic, heme-bound carbene species and a model is provided to rationalize the stereopreference of the protein catalyst. This work shows that myoglobin constitutes a promising and robust scaffold for the development of biocatalysts with carbene-transfer reactivity.
Study on the tandem synthesis of optically active 2-substituted 4 (or 5)-phenyl-1,3-oxazolines
Jiang, Haizhen,Lu, Wenjun,Cai, Yeshan,Wan, Wen,Wu, Shaoxiong,Zhu, Shizheng,Hao, Jian
, p. 2150 - 2156 (2013/03/14)
Optically active (S)-2-aryl-4 (or 5)-phenyl-1,3-oxazolines and (S)-2-fluoroalkyl-4-phenyl-1,3-oxazolines were synthesized from a tandem one-pot reaction of (S)-2-amino-2-phenylethanol with a corresponding carboxylic acid in toluene at 90 °C in the presence of PPh3/CBr4 and excess Et3N. The use of aromatic carboxylic acids were determined to proceed through N-(2-bromo-1-phenyl-ethyl)-arylamides 5 and N-aroyl aziridine intermediates 6, which resulted in the formation of (S)-2-aryl-4-phenyl-1,3- oxazolines and (S)-2-aryl-5-phenyl-1,3-oxazolines, respectively. Concurrently, the reaction with fluorinated aliphatic carboxylic acid substrates proceeded via N-(2-hydroxy-1-phenyl-ethyl)-fluoroalkyl amide intermediates 8, which were converted into N-(2-bromo-1-phenyl-ethyl)-fluoroalkyl amide intermediates 9, and then into (S)-2-fluoroalkyl-4-phenyl-1,3-oxazolines as final products. Reaction mechanisms that mainly passed through the formation of aziridine intermediates 6 in the reaction with aromatic carboxylic acids and the formation of fluoroalkyl amide intermediates 8 and 9 in the reaction with fluorinated aliphatic carboxylic acid were proposed. The acidities of the carboxylic acids that were employed were found to play a key role in the selective formation of various intermediates during this reaction.
Highly stereoselective Ru(ii)-Pheox catalyzed asymmetric cyclopropanation of terminal olefins with succinimidyl diazoacetate
Chanthamath, Soda,Phomkeona, Kesiny,Shibatomi, Kazutaka,Iwasa, Seiji
, p. 7750 - 7752 (2012/09/21)
The Ru(ii)-Pheox complex is an efficient catalyst for the intermolecular cyclopropanation of various terminal olefins with succinimidyl diazoacetate. This catalytic system can perform under mild conditions, and the desired cyclopropane products are obtain
Catalytic asymmetric hydrogenation of N-Boc-imidazoles and oxazoles
Kuwano, Ryoichi,Kameyama, Nao,Ikeda, Ryuhei
supporting information; experimental part, p. 7312 - 7315 (2011/06/24)
Substituted imidazoles and oxazoles were respectively hydrogenated into the corresponding chiral imidazolines and oxazolines (up to 99% ee). The highly enantioselective hydrogenation was achieved by using the chiral ruthenium catalyst, which is generated
A convenient synthesis of 2-oxazolines and 2-benoxazoles with PPh3-DDQ as the dehydrating reagent
Xu, Quancai,Li, Zhengning,Chen, Huiying
experimental part, p. 925 - 932 (2012/01/03)
2-Oxazolines and 2-benoxazoles were synthesized in high yields from acylamino alcohols and acylaminophenols, respectively, with triphenylphosphine- 2,3-dichloro-5,6-dicyanobenzoquinone (PPh3-DDQ) as the dehydrating and activating reagent. The synthesis was accomplished under neutral conditions.
Asymmetric inter- and intramolecular cyclopropanation reactions catalyzed by a reusable macroporous-polymer-supported chiral ruthenium(II)/phenyloxazoline complex
Abu-Elfotoh, Abdel-Moneim,Phomkeona, Kesiny,Shibatomi, Kazutaka,Iwasa, Seiji
supporting information; experimental part, p. 8439 - 8443 (2011/01/05)
Along came poly: A novel macroporous polymer-supported chiral Ru II/pheox catalyst (1, see SEM image) afforded excellent reactivity and enantioselectivity in inter- and intramolecular cyclopropanation reactions with a broad range of substrates. The catalyst showed no leaching and could be reused up to 11-times, even after storage.
A facile synthesis of 2-oxazolines using a PPh3-DDQ system
Xu, Quancai,Li, Zhengning
experimental part, p. 6838 - 6840 (2010/04/29)
A facile and efficient synthesis of 2-oxazolines from N-(2-hydroxyethyl)amides using a triphenylphosphine-2,3-dichloro-5,6-dicyanobenzoquinone (PPh3-DQQ) system is described. The reaction proceeds under neutral and mild conditions, and excellent yields are obtained.
One pot direct synthesis of oxazolines, benzoxazoles, and oxadiazoles from carboxylic acids using the Deoxo-Fluor reagent
Kangani, Cyrous O.,Kelley, David E.,Day, Billy W.
, p. 6497 - 6499 (2007/10/03)
A one-pot, high yield direct synthesis of various 2-substituted oxazolines, benzoxazoles, and 2-oxadiazoles from carboxylic acids using Deoxo-Fluor reagent is described.
