Refernces
10.1002/ejic.201000802
The study focuses on the synthesis and investigation of ruthenium complexes bearing N-H acidic pyrazole ligands and their application in catalytic hydrogenation reactions. The researchers treated chelate ligands containing pyrazole groups with various ruthenium precursors to form complexes with protic N-H groups near the catalytically active ruthenium center. These complexes were characterized by spectroscopic methods and DFT calculations, and their structure and reactivity were analyzed. The study aimed to understand the role of the acidic N-H groups in metal-ligand-bifunctional hydrogenation, where a hydrido ligand and a proton from a protic group are transferred simultaneously. The catalytic performance of these complexes was evaluated through the hydrogenation and transfer hydrogenation of acetophenone, and the results were connected to the ligand's electronic and structural properties. The research provides insights into the design of efficient catalysts for hydrogenation reactions by leveraging the acidic N-H groups in pyrazole ligands.
10.1155/2012/457949
The research focuses on the development of a novel and efficient synthesis method for 1,2,3-thiadiazole and 1,2,3-diazaphosphole derivatives, which exhibit potential anticancer properties. The synthesis initiates with readily available starting materials like camphor and derivatives of acetophenone, and proceeds through a series of optimized steps to yield the target compounds. The study employs the Hurd-Mori and Lalezari methods for the preparation of 1,2,3-thiadiazole and 1,2,3-diazaphosphole derivatives, respectively. Various analytical techniques were utilized to characterize the synthesized compounds, including infrared spectroscopy (IR), mass spectrometry (MS), and proton nuclear magnetic resonance (1H-NMR). The synthesized compounds were then tested for their antibacterial and anticancer activities, with the anticancer activity being evaluated against a breast cancer cell line, and compared with the known anticancer drug Doxorubicin. The experiments involved the use of various ketones as reactants and the analysis of the synthesized compounds' structures and yields, as well as their biological activities.
10.1021/acs.organomet.8b00410
The study focuses on the synthesis and characterization of a series of low-valent molybdenum complexes supported by the pincer ligand (iPr2PCH2CH2)2NH, which were prepared and found to be effective catalysts for the hydrogenation of ketones and olefins. The researchers utilized various chemicals, including Mo(CO)6, NaBHEt3, different acetophenones, chalcone, styrenes, and other substrates for hydrogenation reactions. These chemicals served as precursors for the molybdenum complexes, reducing agents, and substrates to test the catalytic activity of the synthesized complexes. The purpose of these chemicals was to facilitate the creation of new Mo(PNP) pincer complexes and to evaluate their performance in catalytic hydrogenation reactions, which are important in homogeneous catalysis and industrial applications.
10.1021/jo050388m
The study focuses on the total synthesis of lamellarins, a group of marine natural products with significant biological activities, using polymer-supported reagents. The researchers utilized four solid-supported reagents in the multistep synthesis process. Key chemicals included Amberlyst A-26 Br3-, polymer bound pyridine hydrobromide perbromide (PVPHP), and Amberlyst A-26 NaCO3-, which were used for selective keto R-bromination of ortho-substituted acetophenone derivatives to produce monobromination products. These products were then used in condensation reactions with benzyldihydroisoquinoline, mediated by Amberlyst A-26 NaCO3-. The synthesized 2H-pyrrole carbonates underwent intramolecular Friedel-Crafts transacylation and lactonization to provide the lamellarin skeleton. Amberlyst-15 was also used to mediate lactonization reactions, effectively combining two separate steps into one transformation. The purpose of these chemicals was to facilitate selective and efficient synthetic pathways for lamellarins, which are important for establishing structure-activity relationships and investigating their mechanisms of action, particularly in the context of cancer cell lines and multidrug-resistance.
10.1016/j.bmc.2017.08.042
The research focuses on the synthesis, pharmacological activities, and molecular docking studies of pyrazolyltriazoles as potential anti-bacterial and anti-inflammatory agents. The purpose of the study was to prepare and evaluate a series of novel pyrazolyl alcohols, pyrazolyl azides, and pyrazolyltriazoles for their bioactivity profile, specifically targeting anti-bacterial and anti-inflammatory properties. The conclusions drawn from the research indicated that compound 5c exhibited potent anti-bacterial activity against Micrococcus luteus, while compounds 5f, 8b, and 8h demonstrated significant in vitro anti-inflammatory activity. Notably, compound 8h was effective in an in vivo LPS-induced sepsis model in mice, showing a significant reduction in TNF-α levels. The chemicals used in the process included various acetophenones, phenylhydrazine hydrochlorides, Vilsmeier-Haack reagents, sodium borohydride, and a range of alkynes and azides for the synthesis of the target pyrazolyltriazoles, as well as standard drugs like streptomycin and dexamethasone for comparative analysis in the biological assays.
10.1021/ja00244a032
The study investigates the photochemistry of various sulfur-containing ketones, including phenacyl alkyl sulfides, sulfoxides, and sulfones, as well as ring-substituted and a-substituted phenacyl phenyl sulfides. These compounds undergo excited state radical cleavage to form a-keto radicals and sulfur-centered radicals when irradiated. The a-keto radicals are efficiently trapped by benzenethiol, while the sulfur-centered radicals mainly couple. The study finds that the rate of cleavage is influenced by the sulfur oxidation state, with sulfoxides undergoing cleavage at a much higher rate than sulfides and sulfones. The extent of disproportionation to form acetophenone increases with increasing a-alkyl substitution on the ketones. The study also examines the effects of ring substituents on the triplet lifetimes and cleavage rates, concluding that both n,p* and p,p* triplets are intrinsically reactive in these ?-cleavage reactions. The research provides insights into the mechanisms and kinetics of these photochemical reactions, supported by spectroscopic and kinetic data.
10.1016/j.tet.2010.10.076
The research aimed to develop enantioselective divergent approaches for the synthesis of (-)-platensimycin and (-)-platencin, two new class antibiotics with potent activity against multi-resistant bacteria such as MRSA and VRE. The researchers designed a chiral synthetic intermediate with a useful a,b-unsaturated sulfone functionality, which served as a masked ketone and a good Michael acceptor. This intermediate was prepared via a highly enantioselective catalytic asymmetric intramolecular cyclopropanation (CAIMCP) developed in their laboratory. The CAIMCP of a-diazo-b-keto sulfone with CuOTf and bisoxazoline ligand 6 successfully afforded cyclopropane derivatives with high enantiomeric excess. The key intermediate 11 was used to synthesize both (-)-platensimycin and (-)-platencin through different synthetic pathways. The formal enantioselective total syntheses of both compounds were achieved, proving the applicability of the uniquely functionalized tricyclo[4.4.0.0]decene derivative and the usefulness of the CAIMCP in natural product synthesis. The study concluded that the developed chiral intermediate enabled the total syntheses of both antibiotics and could be useful for preparing their new derivatives and congeners.
10.1039/b813890g
The research focuses on the synthesis of novel 5-alkoxymethyl-2-aryl-3-chloropyrroles and 2-aroylpyrroles through the electrophile-induced bromocyclization of N-(1-aryl-2,2-dichloropent-4-enylidene)amines to intermediate 1-pyrrolinium salts. The study investigates the selective conversion of these salts into the target pyrroles by reacting them with alkoxides in the corresponding alcohol or in THF, deviating from the chemistry of c,d-unsaturated a,a-dialkylaldimines. Additionally, the treatment of 5-bromomethyl-1-pyrrolinium bromides with sodium hydroxide in water leads to a new method for synthesizing 2-aroylpyrroles through an unexpected ring transformation of intermediate aziridine derivatives, which can also be isolated. The experiments involved the preparation of N-(1-aryl-2,2-dichloropent-4-enylidene)amines from acetophenone derivatives through a three-step procedure, followed by their cyclization with bromine and subsequent reactions with alkoxides or sodium hydroxide. The analyses used to support the findings include 1H NMR to detect intermediates and crude reaction mixtures, and the yields of the synthesized compounds were reported in a table.
10.1016/j.bmc.2012.02.041
The study investigates the creation and evaluation of a series of novel fused 1,2,4-triazine derivatives for their potential as inhibitors of CYP1A1 activity. CYP1A1 is an enzyme involved in the metabolic activation of various chemical carcinogens, and its inhibition is considered a promising strategy for developing new anticancer drugs. The researchers synthesized compounds such as 4-amino-6-substituted benzyl-3-hydrazinyl-1,2,4-triazin-5(4H)-one (1a–b) and their derivatives (3a–3f, 4a–4i, 6a–6b) through reactions with aldehydes, acetophenones, and other reagents. These compounds were characterized using techniques like 1H NMR, 13C NMR, MS spectra, and X-ray crystallography. The inhibitory effects of these compounds on CYP1A1 activity were tested, revealing that compounds 4e, 5a, 5b, and 6b exhibited the highest inhibitory effects. Docking studies indicated that these triazolotriazine derivatives bind at the interface of substrate recognition sites 2 (SRS2) and 6 (SRS6) on the protein surface, interacting with amino acids ASN214, SER216, and ILE462 through H-bonds. The study suggests that these compounds could serve as leads for developing new chemopreventive anticancer agents.
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