ABSTRACT
Based on aggregation-induced emission (AIE) and twisted intramolecular charge transfer (TICT) mechanisms, a fluorescent probe SWJT-12 for the detection of ClO- was designed by using the CîN bond as a reactive group. This synthesized probe can react with ClO- in a high aqueous phase, and it shows a large Stokes shift (144 nm) and low biological toxicity. Its limit of detection was calculated to be 0.28 µM. Furthermore, SWJT-12 was successfully used for ratiometric imaging of the exogenous hypochlorite anion in living cells.
Subject(s)
Hypochlorous Acid , Optical Imaging , Humans , HeLa Cells , Microscopy, Fluorescence , Fluorescent Dyes/chemistryABSTRACT
A series of lathyrane-type Euphorbia diterpene derivatives featured 3R configuration (H-3ß) were synthesized from natural rich Euphorbia factor L3via modified Mitsunobu reaction based on configuration inversion strategy. The antiproliferation activity and MDR reversal ability of the lathyrane derivatives were evaluated, and the most synthesized compounds showed moderate or strong potencies. Among them, diterpenes 21 (IC50 values of 2.6, 5.2 and 13.1 µM, respectively) and 25 (IC50 values of 5.5, 8.6 and 1.3 µM, respectively) presented the strong cytotoxicity against MCF-7, 4 T1 and HepG2 cells. Meanwhile, derivative 25 exhibited excellent MDR reversal ability with the reversal fold of 16.1 higher than that of verapamil. The cellular thermal shift assay and molecular docking proved direct engagement of diterpene 25 to ABCB1, suggesting 25 could be a promising MDR modulator. Furthermore, the preliminary SARs of these diterpenes were also discussed.
Subject(s)
Antineoplastic Agents , Diterpenes , Euphorbia , Humans , Cell Line, Tumor , Diterpenes/chemical synthesis , Diterpenes/pharmacology , Euphorbia/chemistry , Hep G2 Cells , Molecular Docking Simulation , Molecular Structure , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacologyABSTRACT
Herein, we report that α,ß-unsaturated ketones could be obtained by palladium-catalyzed ring-opening of mono-substituted cyclopropyl ketones efficiently and systematically. (E)-1-Arylbut-2-en-1-ones were generated from aryl cyclopropyl ketones stereoselectively in yields of 23-89% by the Pd(OAc)2/PCy3 catalytic system. The reaction exhibited stereoselectivity (only E products were found) and was suitable for both phenyl and heteroaryl cyclopropyl ketones.
Subject(s)
Ketones , Palladium , Catalysis , Molecular StructureABSTRACT
A study of the scope and limitations of varying the ligand framework around the dinuclear core of FvRu2 in its function as a molecular solar thermal energy storage framework is presented. It includes DFT calculations probing the effect of substituents, other metals, and CO exchange for other ligands on ΔHstorage . Experimentally, the system is shown to be robust in as much as it tolerates a number of variations, except for the identity of the metal and certain substitution patterns. Failures include 1,1',3,3'-tetra-tert-butyl (4), 1,2,2',3'-tetraphenyl (9), diiron (28), diosmium (24), mixed iron-ruthenium (27), dimolybdenum (29), and ditungsten (30) derivatives. An extensive screen of potential catalysts for the thermal reversal identified AgNO3 -SiO2 as a good candidate, although catalyst decomposition remains a challenge.
Subject(s)
Alkadienes/chemistry , Coordination Complexes/chemical synthesis , Cyclopentanes/chemistry , Metals/chemistry , Solar Energy , Catalysis , Coordination Complexes/chemistry , Crystallography, X-Ray , Kinetics , Molecular Conformation , ThermodynamicsABSTRACT
A foray into the exploration of Fe analogues of the (fulvalene)tetracarbonyldiruthenium [FvRu2(CO)4] solar-thermal storage system 1â2 is described. It was facilitated by the development of a convenient synthetic access to the parent [FvFe2(CO)4] 3a and the more soluble di(tert-butyl)fulvalene derivatives 3c and d. Laboratory time scale irradiations (>400 nm) fail to induce photoisomerization, an observation that is explained by the results of time-resolved IR experiments. They show that photoexcitation generates only the short-lived singlet syn biradical of 3 (and a small amount of decarbonylation product), in the absence of the corresponding triplet species required for the occurrence of rearrangement to 4.
Subject(s)
Electric Power Supplies , Iron/chemistry , Organometallic Compounds/chemistry , Ruthenium/chemistry , Solar Energy , Temperature , Molecular Conformation , Organometallic Compounds/chemical synthesis , Quantum Theory , Spectrophotometry, Infrared , Time FactorsABSTRACT
Caught in the light: The fulvalene diruthenium complex shown on the left side of the picture captures sun light, causing initial Ru-Ru bond rupture to furnish a long-lived triplet biradical of synâ configuration. This species requires thermal activation to reach a crossing point (middle) into the singlet manifold on route to its thermal storage isomer on the right through the antiâ biradical.
Subject(s)
Coordination Complexes/chemistry , Photosensitizing Agents/chemistry , Models, Molecular , Molecular Conformation , Oxidation-Reduction , Photochemical Processes , Spectrophotometry, Infrared , Time Factors , X-Ray Absorption SpectroscopyABSTRACT
Mild-mannered Mannich reaction: Highly enantioselective one-pot, three-component Mannich-type reaction of aldehydes, 2-aminophenol, and ketene silyl acetal with 5 mol % of a C(2)-symmetric N,N'-dioxide-based scandium(III) triflate (2:1) complex as the catalyst was achieved under mild conditions (see scheme), which facilitated the asymmetric synthesis of biologically interesting beta-amino esters.
Subject(s)
Cyclic N-Oxides/chemistry , Organometallic Compounds/chemical synthesis , Catalysis , Molecular Structure , Organometallic Compounds/chemistry , Scandium , StereoisomerismABSTRACT
An enantioselective Biginelli reaction that proceeds by a dual-activation route has been developed by using a combined catalyst of a readily available trans-4-hydroxyproline-derived secondary amine and a Brønsted acid. Aromatic, heteroaromatic, and fused-ring aldehydes were found to be suitable substrates for this multicomponent reaction. The corresponding dihydropyrimidines were obtained in moderate-to-good yields with up to 98 % ee under mild conditions. Based on the experimental results and the observed absolute configurations of the products, a plausible transition state has been proposed to explain the origin of the activation and the asymmetric induction.
Subject(s)
Amines/chemistry , Pyrimidines/chemical synthesis , Trifluoroacetic Acid/chemistry , Acetoacetates/chemistry , Benzaldehydes/chemistry , Catalysis , Molecular Structure , Pyrimidines/chemistry , Stereoisomerism , Urea/chemistryABSTRACT
The N,N'-dioxide-Cu(I) complexes have been developed to catalyze the addition of nitromethane to N-tosyl aldimines. The aza-Henry reaction proceeds smoothly affording the corresponding nitro amines in good yields with high enantioselectivities. A catalytic cycle is proposed to explain the origin of reactivity.