491-34-9Relevant articles and documents
Iron-Catalysed Direct Aromatic Amination with N-Chloroamines
Douglas, Gayle E.,Raw, Steven A.,Marsden, Stephen P.
, p. 5508 - 5514 (2019)
An optimized procedure for the direct intra- and intermolecular amination of aromatic C–H bonds with aminium radicals generated from N-chloroamines under iron catalysis is reported. A range of substituted tetrahydroquinolines could be readily prepared, while extension to the synthesis of benzomorpholines was more limited in scope. A direct one-pot variant was developed, allowing direct formal oxidative N–H/C–H coupling.
Reductive: N -methylation of quinolines with paraformaldehyde and H2 for sustainable synthesis of N -methyl tetrahydroquinolines
Wang, Hongli,Huang, Yongji,Jiang, Qi,Dai, Xingchao,Shi, Feng
, p. 3915 - 3918 (2019)
A new and straightforward method was developed for the synthesis of N-methyl-1,2,3,4-tetrahydroquinolines by one-pot reductive N-methylation of quinolines with paraformaldehyde and H2 over Pd/C catalyst. A series of functional MTHQs, including (±)-galipinine and (±)-angustrureine were successfully synthesized in good to excellent yields by applying this simple catalyst system.
Reduction of 1-Formyl-1,2,3,4-Tetrahydroquinoline with Ethyldiphenylsilane
Lukevits, E.,Zablotskaya, A.,Segal, I.
, p. 374 - 375 (1995)
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Photobehavior of mixed π*/ππ* triplets: Simultaneous detection of the two transients, solvent-dependent hydrogen abstraction, and reequilibration upon protein binding
Jornet, Dolors,Tormos, Rosa,Miranda, Miguel A.
, p. 10768 - 10774 (2011)
In the present work, a systematic study on hydrogen abstraction by the excited triplet states of 4-methoxybenzophenone (1) and 4,4′- dimethoxybenzophenone (2) from 1,4-cyclohexadiene (3), 4-methylphenol (4), 1,2,3,4-tetrahydroquinoline (5), and 1-methyl-1,2,3,4-tetrahydroquinoline (6) in different media has been undertaken. Laser flash photolysis (LFP) revealed that in nonpolar solvents, 1 and 2 triplets have a π* configuration with the typical benzophenone-like T-T absorption spectrum (?max ca. 525 nm). Conversely, in aqueous solution, transient absorption spectra with maxima at 450 and 680 nm, attributed to the ππ* triplet, were obtained. Quenching of 1 or 2 triplet by 3 led to ketyl radical formation with rate constants in the range of 106-108 M-1 s -1, being one order of magnitude higher in acetonitrile than in aqueous media. The rate constants of quenching by 4 and 5 were similar in both polar and nonpolar solvents; the highest value was found for 6 in acetonitrile ((6.3 to 6.9) - 109 M-1 s-1). For mechanistic insight, LFP of 1 or 2 in the presence of dimethoxybenzene as electron donor was performed. The results showed that in this case, triplet quenching is favored in aqueous solution. In addition, 2 included in human serum albumin (HSA) was submitted to LFP. The decay kinetics, monitored at 430 nm, fitted well with three lifetimes of 0.45, 1.4, and 14.4 ?s assignable to 2 in bulk solution and in site II or in site I of HSA, respectively. This assignment was confirmed by using oleic acid and ibuprofen as selective displacement probes.
Metal-free reduction of unsaturated carbonyls, quinones, and pyridinium salts with tetrahydroxydiboron/water
Li, Tiejun,Peng, Henian,Tang, Wenjun,Tian, Duanshuai,Xu, Guangqing,Yang, He
, p. 4327 - 4337 (2021/05/31)
A series of unsaturated carbonyls, quinones, and pyridinium salts have been effectively reduced to the corresponding saturated carbonyls, dihydroxybenzenes, and hydropyridines in moderate to high yields with tetrahydroxydiboron/water as a mild, convenient, and metal-free reduction system. Deuterium-labeling experiments have revealed this protocol to be an exclusive transfer hydrogenation process from water. This journal is
Formic acid disproportionation into formaldehyde triggered by vanadium complexes with iridium catalysis under mild conditions inN-methylation
Guo, Yan-Jun,Li, Yang,Zhang, Ping,Zhao, Yu-Rou,Zhou, Chao-Zheng
supporting information, p. 2918 - 2924 (2021/05/05)
Formaldehyde (CH2O) has been used as a key platform reagent in the chemical industry for many decades. Currently, the industrial production of CH2O mainly depends on fossil resources, involving a highly energetic three-step process (200-1100 °C). Herein, we describe renewable formic acid (HCO2H) disproportionation into CH2O triggered by vanadium complexes with iridium catalysis under mild conditions at 30-50 °C inN-methylation. The gram-scale application ofin situgenerated CH2O by HCO2H disproportionation is demonstrated.