A Solvent-Free, One-Step, One-Pot Gewald Reaction for Alkyl-aryl Ketones via Mechanochemistry

Synergistic effect of Cydonia oblonga and its extracted silver nanoparticles for improving antioxidant and antibacterial activity of 3D printed alginate-based hydrogel as wound dressing

The current research studies the synergistic effect of Cydonia oblonga and its extracted nano bio‑silver as a natural and eco-friendly agent for the improvement of three-dimensional (3D)-printed alginate wound dressings. Therefore, Cydonia oblonga extract was first prepared and silver nanoparticles were extracted from it through a green and simple method. The Cydonia oblonga and its extracted bio-based nanoparticles were then added to 3D printing alginate-based ink. Subsequently, a 3D structural extrusion printer was employed to create the porous hydrogel-based wound dressings. The morphological investigation demonstrated that using the extraction method the bio-based silver nanoparticles were successfully prepared, having an average size of 17.95 ± 4.50 nm. The Cydonia oblonga extract showed comparable antioxidant activity to the commercial antioxidant and an excellent total phenol content. In addition, the results showed the combination of Cydonia oblonga extracts/silver nanoparticles significantly improved the antibacterial performance of alginate-based bioinks. In vivo, and in vitro studies confirmed their biocompatibility and significant efficacy in the treatment of burn wounds.

A novel thieno[2,3-d]pyrimidine derivative inhibiting vascular endothelial growth factor receptor-2: A story of computer-aided drug discovery

Following the pharmacophoric features of vascular endothelial growth factor receptor 2 (VEGFR-2) inhibitors, a novel thieno[2,3-d]pyrimidine derivative has been designed and its activity against VEGFR-2 has been demonstrated by molecular docking studies that showed an accurate binding mode and an excellent binding energy. Furthermore, the recorded binding was confirmed by a series of molecular dynamics simulation studies, which also revealed precise energetic, conformational, and dynamic changes. Additionally, molecular mechanics with generalized Born and surface area solvation and polymer-induced liquid precursors studies were conducted and verified the results of the MD simulations. Next, in silico absorption, distribution, metabolism, excretion, and toxicity studies have also been conducted to examine the general drug-like nature of the designed candidate. According to the previous results, the thieno[2,3-d]pyrimidine derivative was synthesized. Fascinatingly, it inhibited VEGFR-2 (IC50  = 68.13 nM) and demonstrated strong inhibitory activity toward human liver (HepG2), and prostate (PC3) cell lines with IC50 values of 6.60 and 11.25 µM, respectively. As well, it was safe and showed a high selectivity index against normal cell lines (WI-38). Finally, the thieno[2,3-d]pyrimidine derivative arrested the growth of the HepG2 cells at the G2/M phase inducing both early and late apoptosis. These results were further confirmed through the ability of the thieno[2,3-d]pyrimidine derivative to induce significant changes in the apoptotic genes levels of caspase-3, caspase-9, Bcl-2 associated X-protein, and B-cell lymphoma 2.

Mechanochemically-Assisted Passerini Reactions: A Practical and Convenient Method for the Synthesis of Novel α-Acyloxycarboxamide Derivatives

A carboxylic acid, an aldehyde, and an isonitrile were combined in a single step (Passerini reaction) under mechanochemical activation to produce several α-acyloxycarboxamide derivatives in high to excellent yields within 15 min of milling. Mechanochemistry, when combined with the diversity provided by multicomponent reactions, enables the efficient synthesis of the target compounds, with great atom economy, shorter reaction times, and experimental simplicity. The method allows for the rapid production of a vast library of complex compounds from a limited number of substrates.

Green methodologies for the synthesis of 2-aminothiophene

Pollution and the rising energy demand have prompted the design of new synthetic reactions that meet the principles of green chemistry. In particular, alternative synthesis of 2-aminothiophene have recently focused interest because 2-aminothiophene is a unique 5-membered S-heterocycle and a pharmacophore providing antiprotozoal, antiproliferative, antiviral, antibacterial or antifungal properties. Here, we review new synthetic routes to 2-aminothiophenes, including multicomponent reactions, homogeneously- or heterogeneously-catalyzed reactions, with focus on green pathways.

Synthesis of Organosulfur and Related Heterocycles under Mechanochemical Conditions

In the last few decades, ball-milling has received tremendous attention as a "green tool" for conducting various challenging organic transformations under transition-metal-free and solvent-free conditions. Organosulfur and related heterocycles are ubiquitous in numerous biologically active molecules with potential applications, and those molecules could be synthesized from readily available starting materials under mechanochemical conditions without using any hazardous chemical or solvent. This synopsis highlights the green strategies developed in recent times to synthesize organosulfur and related heterocycles under ball-milling conditions.

Thiophene Syntheses by Ring Forming Multicomponent Reactions

Thiophenes occur as important building blocks in natural products, pharmaceutical active compounds, and in materials for electronic and opto-electronic devices. Therefore, there is a considerable demand for efficient synthetic strategies for producing these compounds. This review focuses on ring-forming multicomponent reactions for synthesizing thiophenes and their derivatives.

Multicomponent mechanochemical synthesis

Historically, the use of mechanochemical methods in synthesis has been almost negligible, but their perception by the synthetic community has changed in recent years and they are on their way to becoming mainstream. However, the hybridization of mechanochemical synthesis with methodologies designed to increase synthetic efficiency by allowing the generation of several bonds in a single operation has taken off only recently, but it already constitutes a very promising approach to sustainable chemistry. In this context, we provide in this Perspective a critical summary and discussion of the main known synthetic methods based on mechanochemical multicomponent reactions.

Mechanochemical reactions studied by in situ Raman spectroscopy: base catalysis in liquid-assisted grinding

Monitoring byin situRaman spectroscopy of a mechanochemical substitution reaction on a carbonyl group reveals base catalysis akin to catalysis in solution.