Asian Journal of Organic Chemistry最新文献

Among the third-generation solar light harvesting devices, dye-sensitized solar cells (DSSCs) were the most studied solar cell device model in the past decade. To date, DSSCs have achieved maximum power conversion efficiency (PCE) of 15.2%. However, the low molar extinction coefficient and absorptivity over a narrow range of solar spectrum limits their usage for practical purpose. After DSSCs, quantum dot sensitized solar cells (QDSSCs) are the most studied candidates in this decade. A maximum PCE of 18.1% has been reported for QDSSCs so far. Nevertheless, QDSSCs still suffer from the drawback of non-scalable synthesis of QDs, long term instability of perovskite QDs and usage of toxic materials like Cd, Se, and Pb for fabrication of QD sensitized light harvesting devices. The ideal approach for efficient light harvesting is to combine quantum dots and dyes as sensitizers to extract their fullest benefits while eliminating their limitations. In this review, we discuss the fabrication and characterization of dye-QD co-sensitized devices. Further, we compare the PCE and other properties of co-sensitized devices. Finally, we discuss the future research direction of these co-sensitized devices, which can lead to fabrication of stable and efficient photovoltaic devices for practical applications.

Ligands are the important part of a metal-catalyzed process. New ligand designing for metal-catalyzed organic transformations is the focused area of current research. Ligand enabled iron-catalyzed reactions provide sustainable alternatives to the costly metal-based methodologies. Furthermore, the one-pot multicomponent strategies displayed significant attention for the scientific community to access valuable scaffolds. Herein, we have demonstrated new ligand tuned iron-catalyzed one-pot multicomponent reactions for the synthesis of diverse heterocyclic scaffolds. New and very simple “nitrogen–oxygen” (“N─O”) type chelating ligands were prepared and applied successfully for the iron-catalyzed multicomponent cascade reactions enabling the synthesis of diverse heterocyclic scaffolds, including 1,4-dihydropyridines, 4H-pyrans, and aminopyrazoles. Prepared ligands as well as all products were well characterized. Mechanistic studies using UV–visible spectroscopy support the in situ formation of the ligand metal complex. The one pot, three component reactions employ readily available aromatic aldehydes and proceed under mild aqueous conditions through sequential carbon carbon bond forming steps, affording the desired heterocycles in good yields with satisfactory selectivity. The methodology also demonstrates good scalability and broad functional group tolerance, recyclable up to five times, underscoring its practical applicability along with green chemistry metrices.

[8]Circulenes, a class of intriguing polycyclic aromatic hydrocarbons, have garnered considerable attention due to their aesthetically pleasing structures. Despite their unique structural features, the applications of these rigid π-conjugated systems remain far from fully explored due to the inherent challenges in functionalizing them. In this study, we report the synthesis of a water-soluble tetrabenzotetraaza[8]circulene derivative (3) through the introduction of four 2,5,8,11-tetraoxatridecane substituents. The optical properties of 3 were systematically studied in THF/water mixtures, revealing its water-fraction-dependent fluorescence. At 77 K, compound 3 exhibits distinctive phosphorescence with an exceptionally long lifetime of 2.08 s and a phosphorescence quantum yield of 12.3%, both among the highest values of reported hetero[8]circulenes. Additionally, 3 displays a pronounced yellow-green afterglow luminescence that persists for 7.6 s, underscoring its potential for persistent emission applications. This study presents an effective method to modulate the optoelectronic properties of hetero[8]circulene derivatives, offering new opportunities for hetero[8]circulenes as promising functional materials.

A straightforward synthesis of 2-CN-aryl thioethers and 3-aminobenzo[b]thiophenes via metal-free cross-coupling and [4+1] annulation reactions of 1,2-benzisothiazoles with indoles or 1,3-diketones have been developed. Notably, the 1,2-benzisothiazole was used as a novel bifunctional aryl sulfuration reagent through the cleavage of N─S bond and chlorine atom removal. This reaction tolerated a wide scope of substrates under simple reaction conditions and involved the formation of new aryl C─S and C≡N bonds. In addition, the scale-up reaction and post-modification demonstrated the practicability of this protocol.

An unprecedented tandem cyclization reaction for synthesizing 3-alkoxyindoles in one pot was described, utilizing 2-nitrochalcone derivatives and various biomass-derived alcohols under Brønsted base catalysis in a corresponding alcohol solvent system. The method is highly atom-economical and efficient, and structurally diverse 3-alkoxyindoles were prepared in good yields (76%–88%) in only 30 min. In addition, the system has excellent atom economy and green synthesis characteristics, minimizes the generation of by-products, and achieves high-value conversion and sustainable utilization of biomass-derived alcohols. This new method enables the base-catalyzed dehydrogenation of alcohols and the synergistic activity of nitro and α, β-unsaturated ketone structures, and the synergistic activation of multiple bonds under mild conditions.

The synthesis of poly-hetero-aromatic (PHA) compounds via one-pot green synthetic routes has emerged as a prominent and effective approach in contemporary organic synthesis. Throughout the decades, the synthesis of therapeutically important N-heterocyclic compounds has been of interest to chemists. MCRs have been considered as a potential tool in achieving targeted N-PHAs as they exhibit high atom economy by achieving complex scaffolds using simple starting units. MCRs using non-metal catalysts and simpler reaction conditions are strong candidates for a greener synthetic approach. This review summarizes various protocols using only catalytic amounts of Bronsted acids (p-TSA and CSA) or DMSO as the solvent cum reactant for the synthesis of complex quinolines and benzophenanthridines from elemental reagents in a single step. Such molecular frameworks hold substantial importance in drug discovery, as they exhibit a wide spectrum of biological and pharmacological activities. These methodologies assay the synthesis of diverse N-PHAs in a regioselective manner following a greener synthetic approach.

A novel protocol for synthesizing pyrazolo[1,2‑a]indazoles from readily available pyrazolidinones and 2-diazo-1,3-indandiones through the Ir(III)-catalyzed C─H bond activation and intramolecular spiroannulation reaction has been described. This approach provides pyrazolo[1,2‑a]indazoles in moderate to good yields, in which C─C/C─N bonds formed in one pot. In addition, 2-diazo-1,3-indandiones act as C1 synthons under these extremely mild reactions. Generally, this method exhibits high efficiency and broad functional group compatibility. What's more, studies on the activity of selected products against human cancer cells (HeLa) demonstrate their further application in medicinal chemistry.