Bioinspired Semisynthesis and Structure Revisions of Chlorinated Norsesquiterpenoids Rumphellatins A-C.

The first synthesis of chlorine-containing hemiketals, rumphellatins A-C (-), previously inaccessible by means of total synthesis, was achieved starting from commercially available (-)-β-caryophyllene oxide (). Structures of rumphellatins A () and C () were revised, while structures of rumphellatin B () and intermediate rumphellolide C () were confirmed. The study expands availability of exotic norsesquiterpenoids for profiling their biological activity as well as facilitates the elucidation of biosynthetic pathways of their formation.

Multicomponent Synthesis of New Fluorescent Boron Complexes Derived from 3-Hydroxy-1-phenyl-1-pyrazole-4-carbaldehyde.

Novel fluorescent pyrazole-containing boron (III) complexes were synthesized employing a one-pot three-component reaction of 3-hydroxy-1-phenyl-1-pyrazole-4-carbaldehyde, 2-aminobenzenecarboxylic acids, and boronic acids. The structures of the novel heterocyclic compounds were confirmed using H-, C-, N-, F-, and B-NMR, IR spectroscopy, HRMS, and single-crystal X-ray diffraction data. The photophysical properties of the obtained iminoboronates were investigated using spectroscopic techniques, such as UV-vis and fluorescence spectroscopies.

Studies of the Functionalized α-Hydroxy--Quinone Imine Derivatives Stabilized by Intramolecular Hydrogen Bond.

In this work, reactions between 6,7-dichloropyrido[1,2-]benzimidazole-8,9-diones with different benzohydrazides were studied. Nucleophilic substitution at C(6) was followed by isomerization and led to α-hydroxy--quinone imine derivatives. Synthesized compounds represent a combination of several structural motifs: a benzimidazole core fused with α-hydroxy--quinone imine, which contains a benzamide fragment.

A Comparative Study of New Fluorescent Anthraquinone and Benzanthrone α-Aminophosphonates: Synthesis, Spectroscopy, Toxicology, X-ray Crystallography, and Microscopy of .

In this research, we explore the synthesis of and characterize α-aminophosphonates derived from anthraquinone and benzanthrone, focusing on their fluorescence properties and potential applications in confocal laser scanning microscopy (CLSM). The synthesized compounds exhibit notable solvatochromic behavior, emitting fluorescence from green to red across various solvents. Spectroscopic analysis, including H-, C-, and P-NMR, FTIR, and mass spectrometry, confirms the chemical structures.

Investigation of Weak Noncovalent Interactions Directed by the Amino Substituent of Pyrido- and Pyrimido-[1,2-]benzimidazole-8,9-diones.

Quinones are small redox-active molecules that are able to form intra- and intermolecular interactions both in the solid state and in solution. On the basis of 6-amino-substituted pyrido- and pyrimido-[1,2-]benzimidazole-8,9-diones, weak interactions were investigated by single-crystal X-ray and H NMR spectroscopy methods. Crystallization of quinone derivatives containing a -NH-CH- fragment led to the formation of both chiral and achiral crystals.

Semisynthesis of Linariophyllenes A-C and Rumphellolide H, Structure Revisions and Proposed Biosynthesis Pathways.

The first semisynthetic routes toward terrestrial anti-inflammatory natural products linariophyllene A-C and the refined route toward marine natural product rumphellolide H are presented. Among the synthesized target compounds, the correct structure of linariophyllene A was determined to be the diastereomer of the originally proposed structure with an inverted stereocenter at the secondary alcohol. The proposed structures of linariophyllene B and rumphellolide H were confirmed.

Light emission mechanism in dimers of carbene-metal-amide complexes.

Recently an efficient dual electroluminescence from monomers and dimers was observed among the structural examples of the emerging emitter class of carbene-metal-amides (CMAs), allowing the preparation of simple design white organic light emitting diodes (wOLEDs). Here we investigate in detail the light emission mechanism in the dimeric species of CMA emitters on the basis of a copper(I) complex TCP bearing thiazoline carbene and 10-phenothiazine 5,5-dioxide (Ptz) ligands. The X-ray structure for crystals with dimer-only emission was obtained, revealing that emissive aggregates consist of face-to-face stacked molecular pairs with an intermolecular distance of 3.

Synthesis, Biological Activity, and Molecular Modelling Studies of Naphthoquinone Derivatives as Promising Anticancer Candidates Targeting COX-2.

Non-small cell lung cancer (NSCLC) remains a leading cause of cancer-associated mortalities worldwide. Therefore, it is crucial to develop a novel therapeutic option targeting localized and metastatic NSCLC. In this paper, we describe the synthesis and biological activity characterization of naphthoquinone derivatives bearing selective anticancer activity to NSCLC via a COX-2 mediated pathway.

Beta and Gamma Amino Acid-Substituted Benzenesulfonamides as Inhibitors of Human Carbonic Anhydrases.

A series of novel benzenesulfonamide derivatives were synthesized bearing - β,γ-amino acid or - β-amino acid and thiazole moieties and their binding to the human carbonic anhydrase (CA) isozymes determined. These enzymes are involved in various illnesses, such as glaucoma, altitude sickness, epilepsy, obesity, and even cancer. There are numerous compounds that are inhibitors of CA and used as pharmaceuticals.

Thiazoline Carbene-Cu(I)-Amide complexes: Efficient White Electroluminescence from Combined Monomer and Excimer Emission.

Luminescent carbene-metal-amide complexes bearing group 11 metals (Cu, Ag, Au) have recently attracted great attention due to their exceptional emission efficiency and high radiative decay rates (). These materials provide a less costly alternative to organic light-emitting diode (OLED) emitters based on more scarce metals, such as Ir and Pt. Herein, a series of eight Cu(I) complexes bearing as yet unexplored 1,3-thiazoline carbenes have been investigated and analyzed with respect to their light emission properties and OLED application.

Convergent biomimetic semisynthesis of disesquiterpenoid rumphellolide J.

The convergent biomimetic gram-scale synthesis of disesquiterpenoid ester rumphellolide J is described. 4β,8β-Epoxycaryophyllan-5-ol was prepared in 67% yield (1.4 g) from naturally ambudant (-)-β-caryophyllene.

Synthesis of Asymmetric Coupled Polymethines Based on a 7-Chloropyrido[1,2-]benzimidazole-8,9-dione Core.

A synthesis of 7-chloropyrido[1,2-]benzimidazole-8,9-dione derivatives bearing fragments of widely used acceptor units has been performed, and their structures were investigated using the principle of coupled polymethines. Their electronic and electrochemical properties have also been studied. Compounds were isolated in both salt and neutral forms and depending on the introduced substituent can exist as -quinone or -quinone methide.

Carbene-Metal Complexes As Molecular Scaffolds for Construction of through-Space Thermally Activated Delayed Fluorescence Emitters.

The through-space charge transfer (CT) process is observed in Cu(I) carbene-metal-amide complexes, where conventional imidazole or imidazoline N-heterocyclic (NHC) carbene fragments act as inert linkers and CT proceeds between a metal-bound carbazole donor and a distantly situated carbene-bound phenylsulfonyl acceptor. The resulting electron transfer gives a rise to efficient thermally activated delayed fluorescence (TADF), characterized with high photoluminescence quantum yields (Φ up to 90%) and radiative rates () up to 3.32 × 10 s.

An Easy Route to Aziridine Ketones and Carbinols.

-Dimethylaziridine-2-carboxamides react with organolithium reagents yielding 2-aziridinylketones. The reaction with one equivalent of organolithium compound is selective to amide carbonyl at a low (-78 °C) temperature. These ketones, in reaction with organolithium reagents, give symmetrical and unsymmetrical aziridinyl carbinols.

Optimized Monofluoromethylsulfonium Reagents for Fluoromethylene-Transfer Chemistry.

An investigation of the properties and reactivity of fluoromethylsulfonium salts resulted in the redesign of the reagents for fluoromethylene transfer chemistry. The model reaction, fluorocyclopropanation of nitrostyrene, turned out to be a suitable platform for the discovery of more streamlined fluoromethylene transfer reagents. The incorporation of halides on one aryl ring increased the reactivity, and 2,4-dimethyl substitution on the other aryl ring provided a balance between the reactivity/crystallinity of the reagent as well as the atom economy.

Crystal structure of a two-dimensional metal-organic framework assembled from lithium(I) and γ-cyclo-dextrin.

The crystal structure of the polymeric title compound, -poly[[[di-aqua-lithium]-μ-γ-cyclo-dextrin(1-)-[aqua-lithium]-μ-γ-cyclo-dextrin(1-)] pentadecahydrate], {[Li(CHO)(HO)]·15HO} , consists of deprotonated γ-cyclo-dextrin (CD) mol-ecules assembled by lithium ions into metal-organic ribbons that are cross-linked by multiple O-H⋯O hydrogen bonds into sheets extending parallel to (01). Within a ribbon, one Li ion is coordinated by one deprotonated hydroxyl group of the first γ-CD torus and by one hydroxyl group of the second γ-CD torus as well as by two water mol-ecules. The other Li ion is coordinated by one deprotonated hydroxyl and by one hydroxyl group of the second γ-CD torus, by one hydroxyl group of the first γ-CD torus as well as by one water mol-ecule.

Benzoselenophenylpyridine platinum complexes: green versus red phosphorescence towards hybrid OLEDs.

The first examples of phosphorescent platinum complexes bearing 2- and 3-(2-pyridyl)benzo[b]selenophenes (PyBSe) were synthesized and fully characterized. Almost identical ionization potential values (5.6 and 5.

Emission Enhancement by Intramolecular Stacking between Heteroleptic Iridium(III) Complex and Flexibly Bridged Aromatic Pendant Group.

Phosphorescent iridium(III) complexes suffer from a strong aggregation quenching, limiting their use in solution-processed or crystalline organic light-emitting diodes. Here we report how an intramolecular stacking between a flexibly bridged bulky aromatic pendant group and the core of nonionic heteroleptic complex can be exploited to minimize the negative effects of this drawback. The stacked conformation provides a rigid sterical shielding of the polar molecular surface, improving photoluminescence quantum yield of the complex both in solution and crystalline state.

Synthesis of 1-(5-Chloro-2-hydroxyphenyl)-5-oxopyrrolidine-3-carboxylic Acid Derivatives and Their Antioxidant Activity.

A series of novel 1-(5-chloro-2-hydroxyphenyl)-5-oxopyrrolidine-3-carboxylic acid derivatives containing chloro, hydroxyl, isopropyl, nitro, nitroso, and amino substituents at benzene ring and 1-(5-chloro-2-hydroxyphenyl)-5-oxopyrrolidine-3-carbohydrazide derivatives bearing heterocyclic moieties were synthesized. Antioxidant activity of the synthesized compounds was screened by DPPH radical scavenging method and reducing power assay. A number of compounds were identified as potent antioxidants.

Experimental and theoretical study on structure and spectroscopic properties of 2-bromo-3-N-(N',N'-dimethylformamidino) benzanthrone.

The goal of present research is a theoretical and experimental investigation of geometrical structure, electronic properties, absorption and fluorescence spectra prediction for 2-bromo-3-N-(N',N'-dimethylformamidino)benzanthrone. As a result of conformational analysis, two rotamers have been found with a rotational barrier of 5.45 kcal/mol.

Photophysical properties of benzanthrone derivatives: effect of substituent, solvent polarity and hydrogen bonding.

Benzanthrone derivatives are potential fluorescent probes for various chemical and biological environments. A mechanistic understanding of their photophysical properties is pivotal for designing an efficient fluorescence sensor based on the benzanthrone framework. In this study, we report on the effect of chemical substitution on the photophysical properties of two benzanthrone derivatives, namely, 3-(N'-methyl)-piperazino-7H-benzo[de]anthracen-7-one [Me-PBA] and 3-(N'-phenyl)-piperazino-7H-benzo[de]anthracen-7-one [Ph-PBA] in different solvents and solvent mixtures of varying polarities and proticities.

Solvates of Dasatinib: Diversity and Isostructurality.

A series of dasatinib crystalline forms were obtained, and a hierarchical cluster analysis of their powder X-ray diffraction patterns was performed. The resulting dendrogram implies 3 structural groups. The crystal structures of several solvates representing 2 of these groups were determined.

Synthesis, Characterization and Photophysical Properties of Naphtho[2,3-b]Indolizine-6,11-Dione Derivatives.

This communication concerns the synthesis, structural characterization and fluorescent properties of novel naphtho[2,3-b]indolizine-6,11-dione derivatives. The target compound synthesized by one-pot multicomponent reaction between naphthoquinone, indandione and pyridine derivatives.The structures of synthesized compounds were characterized by IR, 1H NMR and 13C NMR analysis.