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.
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.
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.