1120-48-5Relevant articles and documents
Development of new estradiol-cationic lipid hybrids: Ten-carbon twin chain cationic lipid is a more suitable partner for estradiol to elicit better anticancer activity
Sudhakar, Godeshala,Bathula, Surendar Reddy,Banerjee, Rajkumar
, p. 653 - 663 (2014)
The present study illustrates the synthesis and anticancer evaluation of six, ten, twelve and fourteen carbon chain containing cationic lipidated-estradiol hybrids. Previously, we have established the lipidation strategy to introduce anticancer activities in various pharmacophores including estradiol (ES). In this structure activity study the length of the carbon chain is narrowed down between C6-C14 to screen out the most potent anticancer molecule among the class. Among the newly developed ES-cationic lipid conjugates, ten-carbon chain containing derivative, ES-C10 (5c) exhibited 4-12 folds better anticancer activity than the previously established derivative, ES-C8 (5b) in various cancer cells of different origin. Moreover cytotoxicity of this molecule was not observed in non-cancer cells. Notably, in spite of bearing estrogenic moiety, ES-C10 exhibited anticancer activity irrespective of estrogen receptor (ER) expression status. ES-C10 exhibited prominent sub-G0 arrest of cancer cells with concomitant induction of apoptosis and demonstrated significant inhibition of tumor growth in mouse melanoma model. Collectively, ES-C10 exemplifies the development of an anticancer agent with broader activity against cancer cells of different origins.
Chemoselective transfer hydrogenation of nitriles to secondary amines with nickel(II) catalysts
Vermaak, Vincent,Vosloo, Hermanus C.M.,Swarts, Andrew J.
, (2021/07/25)
Herein we report the selective transfer hydrogenation (TH) of nitriles to secondary (2°) amines with simple Ni(II)-catalysts using ammonia borane (AB) as a source of hydrogen (H2). A bis(pyrazolylmethyl)pyridine (L1) or ethylenediamine (L4) ligated Ni(II) pre-catalyst, created in situ, could hydrogenate several aromatic- and aliphatic nitriles in full conversions and isolated yields of up to 88% under ambient temperature and in very short reaction times. Deuterium labelling experiments illustrated the incorporation of a proton on the nitrogen and hydride on the α-carbon of dibenzylamine. Using α-picoline borane, containing no dissociable protons, assisted with the postulation of a two-step TH mechanism of benzonitrile. AB was subjected to dehydrogenation and it was observed that a maximum of 2.96 equivalents of H2 gas could be generated from NiCl2?6H2O/L1.
Highly Selective Hydrogenative Conversion of Nitriles into Tertiary, Secondary, and Primary Amines under Flow Reaction Conditions
Furugen, Chikara,Ito, Naoya,Jiang, Jing,Park, Kwihwan,Sajiki, Hironao,Shimizu, Eisho,Yamada, Tsuyoshi
, (2021/12/13)
Flow reaction methods have been developed to selectively synthesize tertiary, secondary, and primary amines depending on heterogeneous platinum-group metal species under catalytic hydrogenation conditions using nitriles as starting materials. A 10 % Pd/C-packed catalyst cartridge affords symmetrically substituted tertiary amines in good to excellent yields. A 10 % Rh/C-packed catalyst cartridge enables the divergent synthesis of secondary and primary amines, with either cyclohexane or acetic acid as a solvent, respectively. Reaction parameters, such as the metal catalyst, solvent, and reaction temperature, and continuous-flow conditions, such as flow direction and second support of the catalyst in a catalyst cartridge, are quite important for controlling the reaction between the hydrogenation of nitriles and nucleophilic attack of in situ-generated amines to imine intermediates. A wide variety of aliphatic and aromatic nitriles could be highly selectively transformed into the corresponding tertiary, secondary, and primary amines by simply changing the metal species of the catalyst or flow parameters. Furthermore, the selective continuous-flow methodologies are applied over at least 72 h to afford three different types of amines in 80–99 % yield without decrease in catalytic activities.
A multifaceted role of a mobile bismuth promoter in alcohol amination over cobalt catalysts
Bahri, Mounib,Ersen, Ovidiu,Khodakov, Andrei Y.,Kusema, Bright T.,Niu, Feng,Ordomsky, Vitaly V.,Yan, Zhen
, p. 4270 - 4278 (2020/07/14)
Promotion with small amounts of different elements is an efficient strategy for the enhancement of the performance of many heterogeneous catalysts. Supported cobalt catalysts exhibit significant activity in the synthesis of primary amines via alcohol amination with ammonia, which is an economically efficient and environmentally friendly process. Insufficient selectivity to primary amines, low activity and fast cobalt catalyst deactivation remain serious issues restricting the application of alcohol amination in the industry. In this work, we have discovered the multifaceted role of the bismuth promoter, which is highly mobile under reaction conditions, in 1-octanol amination over supported cobalt catalysts. First, the overall reaction rate was enhanced more than twice on promotion with bismuth. Second, the selectivity to primary amines increased 6 times in the presence of Bi at high alcohol conversion. Finally, the bismuth promotion resulted in extremely high stability of the cobalt catalyst. Characterization by XRD, temperature programmed reduction, STEM, CO chemisorption, BET, TGA and FTIR has showed that the enhancement of the catalytic performance on promotion with bismuth is due to better cobalt reducibility, easy removal of strongly adsorbed intermediates and products by the mobile promoter and suppression of amine coupling reactions resulting in secondary and tertiary amines.
One-pot reductive amination of carboxylic acids: a sustainable method for primary amine synthesis
Coeck, Robin,De Vos, Dirk E.
supporting information, p. 5105 - 5114 (2020/08/25)
The reductive amination of carboxylic acids is a very green, efficient and sustainable method for the production of (bio-based) amines. However, with current technology, this reaction requires two to three reaction steps. Here, we report the first (heterogeneous) catalytic system for the one-pot reductive amination of carboxylic acids to amines, with solely H2 and NH3 as the reactants. This reaction can be performed with relatively cheap ruthenium-tungsten bimetallic catalysts in the green and benign solvent cyclopentyl methyl ether (CPME). Selectivities of up to 99% for the primary amine could be achieved at high conversions. Additionally, the catalyst is recyclable and tolerant for common impurities such as water and cations (e.g. sodium carboxylate).
Amination of aliphatic alcohols with urea catalyzed by ruthenium complexes: effect of supporting ligands
Dindar, Sara,Nemati Kharat, Ali
, (2020/09/02)
In the present study, ruthenium-catalyzed amination of alcohols by urea as a convenient ammonia carrier in the presence of free diphosphine ligands has been described. A number of ruthenium-phosphine complexes have been studied among which, [(Cp)RuCl(dppe)] was found as an efficient catalyst for alcohol amination reaction. The crystal structures of two new half-sandwich ruthenium complexes, [(Cp)RuCl(dppe)] and [(C6H6)RuCl2(PHEt2)], were determined by X-ray crystallographic analysis. Also the effect of using different supporting phosphines, ratio of raw materials and reaction temperature on conversion and selectivity was investigated. Under optimum reaction conditions high conversion (98percent) and chemo-selectivity toward secondary amines were obtained.
Sustainable hydrogenation of aliphatic acyclic primary amides to primary amines with recyclable heterogeneous ruthenium-tungsten catalysts
Coeck, Robin,Berden, Sarah,De Vos, Dirk E.
supporting information, p. 5326 - 5335 (2019/10/11)
The hydrogenation of amides is a straightforward method to produce (possibly bio-based) amines. However current amide hydrogenation catalysts have only been validated in a rather limited range of toxic solvents and the hydrogenation of aliphatic (acyclic) primary amides has rarely been investigated. Here, we report the use of a new and relatively cheap ruthenium-tungsten bimetallic catalyst in the green and benign solvent cyclopentyl methyl ether (CPME). Besides the effect of the Lewis acid promotor, NH3 partial pressure is identified as the key parameter leading to high primary amine yields. In our model reaction with hexanamide, yields of up to 83% hexylamine could be achieved. Beside the NH3 partial pressure, we investigated the effect of the catalyst support, PGM-Lewis acid ratio, H2 pressure, temperature, solvent tolerance and product stability. Finally, the catalyst was characterized and proven to be very stable and highly suitable for the hydrogenation of a broad range of amides.
Nanoceria-promoted low Pd-Ni catalyst for the synthesis of secondary amines from aliphatic alcohols and ammonia
Fang,Yan,Vits,Southward,Pera-Titus
, p. 1215 - 1230 (2019/03/12)
This paper describes the preparation of a series of bimetallic Pd-Ni catalysts supported over nanoceria with very low Ni and Pd loading (2-TPR, H2-TPD, STEM-EDS-SDD and XPS. The sequence of impregnation of both metals and the Pd loading affected to an important extent the catalytic activity by conditioning the crystallite size and the Pd and Ni speciation, as well as the reducibility and reversible H2 storage properties. By optimizing the preparation protocols, a 0.5wt% Pd-0.5wt% Ni-Pd/CeO2 formulation prepared by sequential impregnation of the nickel and palladium precursors afforded 80% yield of dioctylamine at almost full conversion [TON = 1160 mmol per mmol (Ni + Pd)surface] in the direct amination reaction of 1-octanol with ammonia at 180 °C for 2 h. Metal leaching during the reaction could be completely avoided. The high catalytic performance of Pd-Ni induced by nanoceria places this catalyst among the best ever reported catalysts for the synthesis of secondary amines.
Selective Transformations of Triglycerides into Fatty Amines, Amides, and Nitriles by using Heterogeneous Catalysis
Jamil, Md. A. R.,Siddiki, S. M. A. Hakim,Touchy, Abeda Sultana,Rashed, Md. Nurnobi,Poly, Sharmin Sultana,Jing, Yuan,Ting, Kah Wei,Toyao, Takashi,Maeno, Zen,Shimizu, Ken-ichi
, p. 3115 - 3125 (2019/04/26)
The use of triglycerides as an important class of biomass is an effective strategy to realize a more sustainable society. Herein, three heterogeneous catalytic methods are reported for the selective one-pot transformation of triglycerides into value-added chemicals: i) the reductive amination of triglycerides into fatty amines with aqueous NH3 under H2 promoted by ZrO2-supported Pt clusters; ii) the amidation of triglycerides under gaseous NH3 catalyzed by high-silica H-beta (Hβ) zeolite at 180 °C; iii) the Hβ-promoted synthesis of nitriles from triglycerides and gaseous NH3 at 220 °C. These methods are widely applicable to the transformation of various triglycerides (C4–C18 skeletons) into the corresponding amines, amides, and nitriles.
N-Methylation of amines and nitroarenes with methanol using heterogeneous platinum catalysts
Jamil, Md.A.R.,Touchy, Abeda S.,Rashed, Md. Nurnobi,Ting, Kah Wei,Siddiki, S.M.A. Hakim,Toyao, Takashi,Maeno, Zen,Shimizu, Ken-ichi
, p. 47 - 56 (2019/02/07)
We report herein the selective N-methylation of amines and nitroarenes with methanol under basic conditions using carbon-supported Pt nanoparticles (Pt/C) as a heterogeneous catalyst. This method is widely applicable to four types of N-methylation reactions: (1) N,N-dimethylation of aliphatic amines under N2, (2) N-monomethylation of aliphatic amines under 40 bar H2, (3) N-monomethylation of aromatic amines under N2, and (4) tandem synthesis of N-methyl anilines from nitroarenes and methanol under 2 bar H2. All these reactions under the same catalytic system showed high yields of the corresponding methylamines for a wide range of substrates, high turnover number (TON), and good catalyst reusability. Mechanistic studies suggested that the reaction proceeded via a borrowing hydrogen methodology. Kinetic results combined with density functional theory (DFT) calculations revealed that the high performance of Pt/C was ascribed to the moderate metal–hydrogen bond strength of Pt.
