91-01-0Relevant articles and documents
Vitvitskaya et al.
, (1975)
Continuous synthesis of peralkylated imidazoles and their transformation into ionic liquids with improved (electro)chemical stabilities
Maton, Cedric,De Vos, Nils,Roman, Bart I.,Stevens, Christian V.,Vanecht, Evert,Brooks, Neil R.,Binnemans, Koen,Schaltin, Stijn,Fransaer, Jan
, p. 3146 - 3157,12 (2012)
A versatile and efficient method to synthesize tetrasubstituted imidazoles via a one-pot modified Debus-Radziszewski reaction and their subsequent transformation into the corresponding imidazolium ionic liquids is reported. The tetrasubstituted imidazoles were also synthesized by means of a continuous flow process. This straightforward synthetic procedure allows for a fast and selective synthesis of tetrasubstituted imidazoles on a large scale. The completely substituted imidazolium dicyanamide and bis(trifluoromethylsulfonyl) imide salts were obtained via a metathesis reaction of the imidazolium iodide salts. The melting points and viscosities are of the same order of magnitude as for their non-substituted analogues. In addition to the superior chemical stability of these novel ionic liquids, which allows them to be applied in strong alkaline media, the improved thermal and electrochemical stabilities of these compounds compared with conventional imidazolium ionic liquids is also demonstrated by thermogravimetrical analysis (TGA) and cyclic voltammetry (CV). Although increased substitution of the ionic liquids does not further increase thermal stability, a definite increase in cathodic stability is observable. Copyright
Walling,Bollyky
, p. 2968 (1961)
Sophisticated Design of Covalent Organic Frameworks with Controllable Bimetallic Docking for a Cascade Reaction
Leng, Wenguang,Peng, Yongsheng,Zhang, Jianqiang,Lu, Hui,Feng, Xiao,Ge, Rile,Dong, Bin,Wang, Bo,Hu, Xiangping,Gao, Yanan
, p. 9087 - 9091 (2016)
Precise control of the number and position of the catalytic metal ions in heterogeneous catalysts remains a big challenge. Here we synthesized a series of two-dimensional (2D) covalent organic frameworks (COFs) containing two different types of nitrogen ligands, namely imine and bipyridine, with controllable contents. For the first time, the selective coordination of the two nitrogen ligands of the 2D COFs to two different metal complexes, chloro(1,5-cyclooctadiene)rhodium(I) (Rh(COD)Cl) and palladium(II) acetate (Pd(OAc)2), has been realized using a programmed synthetic procedure. The bimetallically docked COFs showed excellent catalytic activity in a one-pot addition–oxidation cascade reaction. The high surface area, controllable metal-loading content, and predesigned active sites make them ideal candidates for their use as heterogeneous catalysts in a wide range of chemical reactions.
Synthesis of molecularly imprinted polymer for removal of effective impurity (benzhydrol) from diphenhydramine hydrochloride drug
Hashemi-Moghaddam, Hamid,Alaeian, Mohammad Reza
, p. 643 - 648 (2014)
The present study describes the synthesis and preliminary testing of molecularly imprinted polymers (MIPs) as scavenger resins for removal of the genotoxic impurities (GTI) benzhydrol from active pharmaceutical ingredients (API). A new molecularly imprinted polymer was synthesized using benzhydrol (template molecule), methacrylic acid (functional monomer), ethylene glycol dimethacrylate (cross-linker), 2,2′-azobisisobutironitril (intiator) and chloroform (porogenic solvent). To compare the performance of this polymer, a control polymer or non-imprinted polymer (NIP) was prepared under the same conditions without the use of template molecule. The synthesized polymers were characterized by FT-IR spectroscopy. Selectivity of the molecularly imprinted polymer for absorption benzhydrol impurities through adsorption experiments reviews and the results were compared with the adsorption of impurities by NIP. Various parameters were optimized such as time, pH, type of eluent for elution of impurities from polymer, concentration of sample and saturation of polymer. The proposed method was applied for removal of benzhydrol from Diphenhydramine hydrochloride syrup and passing it through the MIPs led to the quantitative removal of benzhydrol. The present work describes the synthesis and preliminary testing of molecularly imprinted polymers (MIPs) as scavenger resins for removal of the genotoxic impurities (GTI) benzhydrol from active pharmaceutical ingredients (API). Copyright
Transfer hydrogenation catalysis by a N-heterocyclic carbene iridium complex on a polyoxometalate platform
Modugno, Gloria,Monney, Angele,Bonchio, Marcella,Albrecht, Martin,Carraro, Mauro
, p. 2356 - 2360 (2014)
A divacant Keggin polyanion has been decorated with a N-heterocyclic carbene (NHC) iridium(I) organometallic complex to provide a molecular model of an Ir-based supported catalyst. The characterization of the hybrid compound has been performed by multinuc
Hydrosilylation of Aldehydes and Ketones Catalyzed by a 2-Iminopyrrolyl Alkyl-Manganese(II) Complex
Cruz, Tiago F. C.,Veiros, Luís F.,Gomes, Pedro T.
, p. 1195 - 1206 (2022/01/11)
A well-defined and very active single-component manganese(II) catalyst system for the hydrosilylation of aldehydes and ketones is presented. First, the reaction of 5-(2,4,6-iPr3C6H2)-2-[N-(2,6-iPr2C6H3)formimino]pyrrolyl potassium (KL) and [MnCl2(Py)2] afforded the binuclear 2-iminopyrrolyl manganese(II) pyridine chloride complex [Mn2{κ2N,N′-5-(2,4,6-iPr3C6H2)-NC4H2-2-C(H)═N(2,6-iPr2C6H3)}2(Py)2(μ-Cl)2] 1. Subsequently, the alkylation reaction of complex 1 with LiCH2SiMe3 afforded the respective (trimethylsilyl)methyl-Mn(II) complex [Mn{κ2N,N′-5-(2,4,6-iPr3C6H2)-NC4H2-2-C(H)═N(2,6-iPr2C6H3)}(Py)CH2SiMe3] 2 in a good yield. Complexes 1 and 2 were characterized by elemental analysis, 1H NMR spectroscopy, Evans' method, FTIR spectroscopy, and single-crystal X-ray diffraction. While the crystal structure of complex 1 has been identified as a binuclear entity, in which the Mn(II) centers present pentacoordinate coordination spheres, that of complex 2 corresponds to a monomer with a distorted tetrahedral coordination geometry. Complex 2 proved to be a very active precatalyst for the atom-economic hydrosilylation of several aldehydes and ketones under very mild conditions, with a maximum turnover frequency of 95 min-1, via a silyl-Mn(II) mechanistic route, as asserted by a combination of experimental and theoretical efforts, the respective silanes were cleanly converted to the respective alcoholic products in high yields.
Site-selective D2O-mediated deuteration of diaryl alcoholsviaquantum dots photocatalysis
Li, Xu-Bing,Nan, Xiao-Lei,Tung, Chen-Ho,Wang, Yao,Wu, Li-Zhu
supporting information, p. 6768 - 6771 (2021/07/13)
Owing to the high synthetic value of deuteration in the pharmaceutical industry, we describe herein the conversion of a range of aromatic ketones to deuterium-labeled products in good to excellent yields. Efficient and site-selective deuteration of benzyl alcohols by D2O with visible light irradiation of quantum dots (QDs), together with gram-scale synthesis and photocatalyst recycling experiments indicated the potential of the developed method in practical organic synthesis.
Enhanced catalytic activity of one-dimensional CdS @TiO2 core-shell nanocomposites for selective organic transformations under visible LED irradiation
Eskandari, Parvin,Kazemi, Foad,Ramdar, Moosa,Zand, Zahra
, (2021/07/10)
In this study, we are interested in the photocatalytic activity under visible LED irradiation of one- dimensional (1D) CdS @TiO2 core–shell nanocomposites (CSNs) prepared through a facile and convenient method. For the synthesis of 1D CdS@TiO2 core/shell structure, titania source (Tetrabutyl titanate) was hydrolyzed by water vapor transmission on the surface of CdS nanowires (NWs) which were prepared via solvothermal method. The characterization of 1D CdS@TiO2 core–shell nanocomposites (CdS@TiO2 CSNs) was performed using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–Vis spectroscopy, and UV–Vis diffuse reflectance spectroscopy (DRS). The as-synthesized sample was utilized for the selective reduction of nitro compounds to benzimidazole and anilide, and also the reduction of benzophenones to alcohol under blue LED irradiation. The 1D CdS@TiO2 CSNs exhibited enhanced photoactivity compared with the pure TiO2, CdS nanowires and commercial TiO2-P25. The excellent reusability of the photocatalyst was examined for six runs. The results demonstrated that the prepared sample has the potential to provide a promising visible light-driven photocatalyst for other organic transformations.