212695-46-0Relevant academic research and scientific papers
Cyclometalated Half-Sandwich Iridium Complex for Catalytic Hydrogenation of Imines and Quinolines
Yao, Zi-Jian,Lin, Nan,Qiao, Xin-Chao,Zhu, Jing-Wei,Deng, Wei
, p. 3883 - 3892 (2018/11/24)
Several C,N-chelate cyclometalated half-sandwich iridium-based catalysts for imines and quinoline derivatives reduction have been prepared through metal-mediated C-H bond activation based on benzothiazole ligands. These iridium complexes exhibited high catalytic activity for hydrogenation of various types of imines with high yields. The most active catalyst was obtained from methoxyl substituted complex 2, showing the catalytic TOF value of 975 h-1 for the reduction of imine 6a. Additionally, these half-sandwich complexes also showed high efficiency for the catalytic hydrogenation of N-heterocyclic quinoline derivatives. Good catalytic activity was displayed for various kinds of substrates with either electron-donating or electron-withdrawing groups. Complexes 1-5 were fully characterized by NMR, IR, and elemental analysis. Molecular structures of complexes 1 and 4 were further confirmed by X-ray diffraction analysis.
A simple iridicycle catalyst for efficient transfer hydrogenation of n-heterocycles in water
Talwar, Dinesh,Li, Ho Yin,Durham, Emma,Xiao, Jianliang
supporting information, p. 5370 - 5379 (2015/03/30)
A cyclometalated iridium complex is shown to catalyse the transfer hydrogenation of various nitrogen heterocycles, including but not limited to quinolines, isoquinolines, indoles and pyridinium salts, in an aqueous solution of HCO2H/HCO2Na under mild conditions. The catalyst shows excellent functional-group compatibility and high turnover number (up to 7500), with catalyst loadings as low as 0.01 mol % being feasible. Mechanistic investigation of the quinoline reduction suggests that the transfer hydrogenation proceeds via both 1,2- and 1,4-addition pathways, with the catalytic turnover being limited by the step of hydride transfer. An easily accessible iridicycle catalyst effects the transfer hydrogenation of a wide variety of N-heterocycles in water, including quinolines, isoquinolines, indoles, quinoxalines, and pyridines. The catalyst shows excellent functional-group compatibility and high turnover number (up to 7500), even with low catalyst loadings.
Thiazolo[5,4,3-ij]quinolines, preparation and medicines containing the same
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, (2008/06/13)
Compounds of formula (I): their racemates, enantiomers, diastereoisomers and inorganic acid salts and organic acid salts thereof, processes for preparing them and the medicaments containing them are discussed.
Selectivity of Hydrogenations. Part 4. 6- and 8-Substituted Quinaldines. Yield of Tetrahydroderivatives and Basicities of Quinolines
Hoenel, Michael,Vierhapper, Friedrich W.
, p. 1219 - 1228 (2007/10/02)
Hydrogenation of 6- or 8-R-substituted quinaldines over platinum in trifluoracetic acid gave higher yields (ca.90percent) of 5,6,7,8-tetrahydroderivatives than hydrogenation of the corresponding quinolines.The pKa-values of 20 quinolines and quinaldines were determined by measuring the half-neutralisation potentials in acetic anhydride.More basic quinolines gave higher yields of 5,6,7,8-tetrahydroproduct; exceptions are 6- and 8-methylquinoline and 8-tert. butylquinoline.Explanations for these observations are suggested. - Keywords:Catalytic hydrogenation; PKa-Values; Quinaldines; Quinolines; 5,6,7,8-Tetrahydroquinolines, yields of.
