90-97-1Relevant academic research and scientific papers
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.
Ruthenium(II) Complex of a Tridentate Azoaromatic Pincer Ligand and its Use in Catalytic Transfer Hydrogenation of Aldehydes and Ketones with Isopropanol
Saha, Tanushri,Prasad Rath, Santi,Goswami, Sreebrata
, p. 1455 - 1461 (2021/05/18)
In this work, a new Ru(II) complex with the redox-active pincer 2,6-bis(phenylazo)pyridine ligand (L) is reported which acts as a metal-ligand bifunctional catalyst for transfer hydrogenation reactions. The isolated complex [(L)Ru(PMe2Ph)2(CH3CN)](ClO4)2; [1](ClO4)2 is characterized by a host of spectroscopic measurements and X-ray structure determination. It is diamagnetic and single-crystal X-ray structure analysis reveals that [1]2+ adopts a distorted octahedral geometry where L binds Ru center in meridional fashion. The observed elongation in the coordinated azo bond length (1.29 ?) is attributed to the extensive π-back bonding, dπ(RuII)→π*(azo)L. The complex [1](ClO4)2 acts as an efficient catalyst, which brings about catalytic transfer hydrogenation reactions of a broad array of aldehydes and ketones in isopropanol and in inert conditions. The selectivity of the catalyst for aldehyde reduction over the other reducible functional groups such as nitro, nitrile, ester etc was also investigated. Mechanistic studies, examined by suitable control reactions and isotope labelling experiments, indicate synergistic participation of both ligand and metal centres via the formation of a fleeting Ru?H intermediate and hydrogen walking to the coordinated azo function of L.
Cationic ruthenium(II)–NHC pincer complexes: Synthesis, characterisation and catalytic activity for transfer hydrogenation of ketones
Yadav, Dibya,Misra, Shilpi,Kumar, Dheeraj,Singh, Suryabhan,Singh, Amrendra K.
, (2021/05/12)
Cationic ruthenium pincer complexes, [Ru(CNC)(CO)(PPh3)Cl]X (CNC = 2,6-bis(1-methylimidazol-2-ylidene)-pyridine, X = Cl? [1a], PF6? [1b]), [Ru(CNC)(PPh3)2Cl]X (X = Cl? [2a], PF6? [2b]) and [Ru(CNC)(PPh3)2(H)]X (X = Cl? [3a], PF6? [3b]) with triphenylphosphine, CO and halides as coligands have been synthesised and characterised by 1H, 13C, 31P NMR, mass and single-crystal X-ray crystallography. The application of Ru complexes in the transfer hydrogenation of a wide range of ketones with 2-propanol as the hydrogen source is explored. The in situ transformations observed during the synthesis help understand and suggest a plausible mechanism via the hydride complex 3b. All complexes appear to be efficient catalyst precursors for transfer hydrogenation of ketones.
Synthesis and biological evaluation of 1‐(Diarylmethyl)‐1h‐1,2,4‐triazoles and 1‐(diarylmethyl)‐1h‐imidazoles as a novel class of anti‐mitotic agent for activity in breast cancer
Ana, Gloria,Kelly, Patrick M.,Malebari, Azizah M.,Noorani, Sara,Nathwani, Seema M.,Twamley, Brendan,Fayne, Darren,O’boyle, Niamh M.,Zisterer, Daniela M.,Pimentel, Elisangela Flavia,Endringer, Denise Coutinho,Meegan, Mary J.
, p. 1 - 59 (2021/03/16)
We report the synthesis and biochemical evaluation of compounds that are designed as hybrids of the microtubule targeting benzophenone phenstatin and the aromatase inhibitor letrozole. A preliminary screening in estrogen receptor (ER)‐positive MCF‐7 breast cancer cells identified 5‐((2H‐1,2,3‐triazol‐1‐yl)(3,4,5‐trimethoxyphenyl)methyl)‐2‐methoxyphenol 24 as a potent antiproliferative compound with an IC50 value of 52 nM in MCF‐7 breast cancer cells (ER+/PR+) and 74 nM in triple‐negative MDA‐MB‐231 breast cancer cells. The compounds demonstrated significant G2/M phase cell cycle arrest and induction of apoptosis in the MCF‐7 cell line, inhibited tubulin polymerisation, and were selective for cancer cells when evaluated in non-tumorigenic MCF‐10A breast cells. The immunofluorescence staining of MCF‐7 cells confirmed that the compounds targeted tubulin and induced multinucleation, which is a recognised sign of mitotic catastrophe. Computational docking studies of compounds 19e, 21l, and 24 in the colchicine binding site of tubulin indicated potential binding conformations for the compounds. Compounds 19e and 21l were also shown to selectively inhibit aromatase. These compounds are promising candidates for development as antiproliferative, aromatase inhibitory, and microtubule‐disrupting agents for breast cancer.
Trivalent Rare-Earth Metal Amide Complexes as Catalysts for the Hydrosilylation of Benzophenone Derivatives with HN(SiHMe2)2 by Amine-Exchange Reaction
Shinohara, Koichi,Tsurugi, Hayato,Anwander, Reiner,Mashima, Kazushi
supporting information, p. 14130 - 14136 (2020/10/06)
The rare-earth metal complexes Ln(L1)[N(SiHMe2)2](thf) (Ln=La, Ce, Y; L1=N,N′′-bis(pentafluorophenyl)diethylenetriamine dianion) were synthesized by treating Ln[N(SiHMe2)2]3(thf)2 with L1H2. The lanthanum and cerium derivatives are active catalysts for the hydrosilylation of benzophenone derivatives with HN(SiHMe2)2. An amine-exchange reaction was revealed as a key step of the catalytic cycle, in which Ln?Si?H β-agostic interactions are proposed to promote insertion of the carbonyl moiety into the Si?H bond.
Photo-induced phosphorus radical involved semipinacol rearrangement reaction: Highly synthesis of γ-oxo-phosphonates
Wang, Chunhai,Huang, Xiaoling,Liu, Xueting,Gao, Suqian,Zhao, Bin,Yang, Shangdong
supporting information, p. 677 - 680 (2019/08/27)
Hydroxyphosphoric acids display the unique biological activities, and they have some attractive prospects as clinical drug moleculars. Herein, a new approach for the synthesis of γ-oxo-phosphonates (the precursor of hydroxyphosphoric acid) has been established through the semipinacol rearrangement tactic involved the photo-induced phosphorus radical process. Most important, this transformation is avoid of the external oxidants, and occurs very well under the sunlight irradiation, meanwhile the γ-oxo-phosphonate was easily derivatized to obtain γ-hydroxyphosphoric acid, thus highlights the synthesis value of this method.
Diaryl hydroxylamines as pan or dual inhibitors of indoleamine 2,3-dioxygenase-1, indoleamine 2,3-dioxygenase-2 and tryptophan dioxygenase
Winters, Maria,DuHadaway, James B.,Pham, Khoa N.,Lewis-Ballester, Ariel,Badir, Shorouk,Wai, Jenny,Sheikh, Eesha,Yeh, Syun-Ru,Prendergast, George C.,Muller, Alexander J.,Malachowski, William P.
supporting information, p. 455 - 464 (2018/11/25)
Tryptophan (Trp) catabolizing enzymes play an important and complex role in the development of cancer. Significant evidence implicates them in a range of inflammatory and immunosuppressive activities. Whereas inhibitors of indoleamine 2,3-dioxygenase-1 (IDO1) have been reported and analyzed in the clinic, fewer inhibitors have been described for tryptophan dioxygenase (TDO) and indoleamine 2,3-dioxygenase-2 (IDO2) which also have been implicated more recently in cancer, inflammation and immune control. Consequently the development of dual or pan inhibitors of these Trp catabolizing enzymes may represent a therapeutically important area of research. This is the first report to describe the development of dual and pan inhibitors of IDO1, TDO and IDO2.
Two-component boronic acid catalysis for increased reactivity in challenging Friedel-Crafts alkylations with deactivated benzylic alcohols
Ang, Hwee Ting,Rygus, Jason P. G.,Hall, Dennis G.
supporting information, p. 6007 - 6014 (2019/06/24)
A general and efficient boronic acid catalyzed Friedel-Crafts alkylation of arenes with benzylic alcohols was previously developed for the construction of unsymmetrical diarylmethane products (X. Mo, J. Yakiwchuk, J. Dansereau, J. A. McCubbin and D. G. Hall, J. Am. Chem. Soc., 2015, 137, 9694). Highly electron-deficient benzylic alcohols, however, were ineffective coupling partners due to the increased difficulty of C-O bond ionization. Herein, we report the use of perfluoropinacol as an effective co-catalyst to improve the reactivity of a boronic acid catalyst in the Friedel-Crafts benzylations of electronically deactivated primary and secondary benzylic alcohols. According to spectroscopic studies, it is believed that perfluoropinacol condenses with the arylboronic acid catalyst to form a highly electrophilic and Lewis acidic boronic ester. This in situ formed species enables a more facile ionization of the benzylic alcohols likely through a mode of activation promoted by a Lewis acid assisted hydronium Br?nsted acid generated from the interactions of the transient boronic ester with hexafluoroisopropanol solvent and water.
Synthesis and biological evaluation of new N-substituted 4-(arylmethoxy)piperidines as dopamine transporter inhibitors
Lapa, Gennady B.,Lapa, Alla A.
, p. 203 - 205 (2019/04/25)
The library of new N-substituted 4-(arylmethoxy)piperidines as dopamine transporter inhibitors was designed and synthesized. H-Bond donors in piperidine ring were found to be important for reduced locomotor activity in mice. 4-[Bis(4-fluorophenyl)methoxy]piperidine has IC50 17.0 ± 1.0 nm for dopamine transporter and locomotor activity, which is lower than that for cocaine.
Half-sandwich Ru (II) complexes containing (N, O) Schiff base ligands: Catalysts for base-free transfer hydrogenation of ketones
Satheesh,Sathish Kumar, Pushpanathan N.,Kumara, P. Raghavendra,Karvembu, Ramasamy,Hosamani, Amar,Nethaji
, (2019/08/07)
Two new half-sandwich Ru (II)(p-cymene) complexes (1 and 2) containing dopamine-based (N, O) Schiff base ligands (L1H and L2H) were synthesized and characterized by FT-IR, UV–Visible and 1H & 13C NMR spectral techniques, and elemental analyses. The spectroscopic and analytical data revealed monobasic bidentate coordination of the ligands with Ru ion. The molecular structures of L1H, L2H and 2 were further confirmed by single crystal X-ray diffraction study. Complexes 1 and 2?have been employed as catalysts in the transfer hydrogenation of ketones using 2-propanol as a hydrogen source at 85?°C under base-free condition. Good to the excellent yield of secondary alcohols, gram scale synthesis, and high TON and TOF made this catalytic system interesting.
