Beilstein Journal of Organic Chemistry最新文献

Organophosphorus compounds are important in synthetic organic chemistry and pharmaceutical applications due to their diverse biological activities. In this study, we synthesized three novel glycidyl esters of phosphorus acids 1-3 via the condensation of chlorophosphine oxides or phosphorus oxychloride with glycidol in the presence of a base, obtaining products with high purity and moderate to excellent yields. Their cytotoxic potential was evaluated using the MTT assay on human fibroblasts (HSF), prostate cancer (PC-3), and breast cancer (MCF7) cell lines, revealing moderate preferential cytotoxicity toward cancer cells, particularly in the case of MCF7. Additionally, linear sweep voltammetry (LSV) studies on human serum albumin (HSA) were conducted to investigate their alkylating properties. The electrochemical results suggest that these compounds effectively modify albumin, highlighting their potential as reactive anticancer agents. These findings provide important insights into the synthesis, cytotoxic activity, and biochemical reactivity of glycidyl esters of phosphorus acids, underscoring their potential as lead structures for further development in anticancer drug discovery and pharmaceutical research.

A series of nitrogen (N)-doped macrocycles was successfully synthesized through palladium-catalyzed arylation. X-ray crystallographic characterization revealed the formation of isomeric products depending on the substituents on the N atoms. Notably, two intrinsically chiral macrocycles MC1 and MC3 with C ₁ symmetry were successfully obtained. These macrocycles exhibit exceptional photophysical properties, particularly remarkable high fluorescence quantum yields (Φ_F up to 0.69). Furthermore, enantiomeric resolution of inherent chiral MC1 was achieved using preparative chiral HPLC, enabling detailed investigation of its chiroptical behavior through circular dichroism and circularly polarized luminescence spectroscopy.

The stereoselective electroreductive intramolecular coupling of chiral diimines of aromatic aldehydes with trans-1,2-diaminocyclohexane for the synthesis of enantiopure tetrasubstituted piperazines has been investigated by an electrochemical approach. The methodology was successfully developed under both batch and continuous flow conditions, and afforded enantiomerically pure products with complete stereoselectivity. Substrates bearing electron-donating or electron-withdrawing groups on the aromatic rings provided good to excellent yields, indicating that both types of substituents are well tolerated under the reaction conditions. Although modest yields were obtained under flow conditions, the continuous process afforded higher productivities and space-time yields than the batch reactions due to a short residence time. This work provides a mild, efficient, and scalable alternative to traditional methods for the synthesis of tetrasubstituted enantiopure piperazines, with potential applications in the preparation of chiral ligands.

Oxindoles are an important class of compounds with significant biological activities. Spirocyclic derivatives are present in a variety of natural products. We describe here the formation of spirooxindoles using an intermolecular nitrone cycloaddition reaction. The nitrone dipole was prepared in situ by cyclisation of an oxime, itself prepared in situ from an aldehyde. The stereochemistry of one of the spirooxindoles was determined by single crystal X-ray diffraction studies via crystallisation using encapsulated nanodroplet crystallisation (ENaCt) protocols. The chemistry involves cascade or tandem condensation, cyclisation, and cycloaddition as an efficient strategy for the rapid formation of complex spirocyclic products that could have value for the formation of novel, bioactive oxindoles.

Chiral molecules, distinguished by nonsuperimposability with their mirror image, play crucial roles across diverse research fields. Molecular chirality is conventionally categorized into the following types: central chirality, axial chirality, planar chirality and helical chirality, along with the more recently introduced inherent chirality. As one of the most prominent chiral organocatalysts, chiral phosphoric acid (CPA) catalysis has proven highly effective in synthesizing centrally and axially chiral molecules. However, its potential in the asymmetric construction of other types of molecular chirality has been investigated comparatively less. This Review provides a comprehensive overview of the recent emerging advancements in asymmetric synthesis of planarly chiral, helically chiral and inherently chiral molecules using CPA catalysis, while offering insights into future developments within this domain.

We systematically lipophilized an amine-based metal-organic framework (MOF) catalyst and applied the functionalized MOFs to the Knoevenagel condensation reaction. A well-defined MOF material composed of both amine- and hydroxy-bearing linkers was reacted with a series of aliphatic isocyanates (isopropyl, tert-butyl, n-hexyl, and tetradecyl) and, incongruously, was found to preferentially react at the hydroxy groups. This selective functionalization yielded MOFs in which the catalytically active amines are confined within highly lipophilic pores, reminiscent of many enzyme active sites. We determined that systematically increasing the lipophilicity of the pores results in a commensurate increase of catalyst efficiency.

Approaching the vast, colourful world of photoswitches from a different field of study or as an undergraduate student may be overwhelming: azobenzene is undoubtedly the most famous due to its easy synthesis and the extensively studied properties. However, there are several photoswitch classes beyond azobenzene with interesting properties that can be tailored to meet one's needs. In this tutorial review, we aim to explain the important terminology and discuss the synthesis, switching mechanisms, and properties of seven interesting photoswitch classes, namely azoheteroarenes, diazocines, indigoid photoswitches, arylhydrazones, diarylethenes, fulgides, and spiropyrans.

Thioformylium methylide, which is readily generated from chloromethyl(trimethylsilyl)methyl sulfide by the action of fluoride, is used for the synthesis of spirocyclic derivatives from arylidene-azolones. Four types of the corresponding heterocycles have been studied. A series of 7-thia-3-azaspiro[4.4]nonan-4-ones was obtained with yields varying from 17 to 99%. The stereochemical study revealed selective formation of single either cis or trans stereoisomers, dependent on the heterocycle core used.

Herein, we report a highly efficient, environmentally benign protocol for the domino synthesis of 2,4-disubstituted and 4-substituted quinoline molecules. The developed strategy involves an earth-abundant Fe-catalyzed C(sp²)-C(sp²) bond cleavage of styrene, followed by the hydroamination of the cleaved synthons with arylamines and subsequent C-H annulation to yield two valuable quinoline derivatives. Key features of this protocol include the use of O₂ as an ideal, green oxidant, operational simplicity and scalability, high atom- and step-economy, and cost-effectiveness, collectively enabling the single-step synthesis of two medicinally relevant N-heterocycles in excellent combined yields.

Both chiral bisoxazolines and bisimidazolines are efficient chiral ligands in metal-catalyzed asymmetric organic transformations. Chiral cyclohexane-linked bisimidazolines were prepared from optically active cyclohexane-1,2-dicarboxylic acid and 1,2-diphenylethane-1,2-diamines via the monosulfonylation of 1,2-diphenylethane-1,2-diamines, condensation of N-sulfonylated 1,2-diphenylethane-1,2-diamines and cyclohexane-1,2-dicarboxylic acid, and the final cyclization with the in situ generated Hendrickson reagent.