Nitrene-transfer from azides to isocyanides: Unveiling its versatility as a promising building block for the synthesis of bioactive heterocycles.

Cross-coupling azide and isocyanide have recently gained recognition as ideal methods for efficiently synthesizing asymmetric carbodiimides. This reaction exhibits high reaction rates, efficiency, and favorable atom/step/redox economy. It enables the nitrene-transfer process, facilitating the formation of C-N bonds and providing a direct and cost-effective synthetic strategy for generating diverse carbodiimides. These carbodiimides are highly reactive compounds that can undergo in-situ transformations into various functional groups and organic compounds, including heterocycles. Developing one-pot and tandem processes in this field has significantly contributed to advancements in organic chemistry. Moreover, the demonstrated utility of these architectural motifs extends to areas such as chemical biology and medicinal chemistry, further highlighting their potential in various scientific applications.

Critical Review on Balanites aegyptiaca Delile: Phytoconstituents, Pharmacological Properties and Nanointerventions.

Balanites aegyptiaca Delile (BA) is an enduring xerophytic woody and spinous flowering tree and is commonly known as desert date or Ingudi (Hingot). It belongs to the family Zygophyllaceae, which is specific to be drought areas of Nigeria, Africa, South Asia and India (Rajasthan). In Ayurveda, this traditional medicinal plant is reported for the management of jaundice, syphilis, yellow fever, metabolic disorders, liver, and spleen problems. The main aim of the review is to compile its medicinal uses and further advancements to showcase the promises inherited in various parts of the plant for the benefit of mankind. As per the literature survey, various researchers have focused on the detailed investigation of BA including the phytopharmacological evidence, chemical constituents, nano-formulations, commercialized products, and clinical trials. Several remarkable scaffolds and isolated compounds like diosgenin, yamogenin, balanitin1/2, balanitin 3, bal4/5, bal6/7, rutin-3-glycosides, 3,7-diglycosides, (3, 12, 14, 16)-(12-hydroxycholest-5-ene-3,16-diyl-bis)-D-glucopyranoside and balanitoside have been identified. Additionally, this traditional plant has been scientifically proven by in vitro and in vivo. Based on the complete review of this plant, most of the compounds have been isolated from the fruit and kernel part. Additionally, based on the literature, a histogram was developed for pharmacological activity in which antidiabetic study was found to be more compared to other pharmacological activity. As a spinous desert dates, this plant needs to be explored more to bring out newer phytochemicals in the management of various diseases.

The Custom R Group Enumeration with Various R Group Libraries at Designated Sites on Amphotericin B.

BACKGROUND: Amphotericin B is a gold-standard drug, particularly for the treatment of systemic fungal infections. However, its low solubility and permeability limit its application. To improve its bioavailability, AmB may be conjugated with various water-soluble auxiliary groups. METHODS: Custom R group Enumeration was used at the designated sites of Amphotericin B. The designated sites taken into consideration are the carboxyl moiety of the aglycone part and the amine moiety of the glycone part of Amphotericin B for Enumeration purposes. The enumerated molecules were subjected to QikProp properties. RESULTS: We identified fourteen hits with improved predicted aqueous solubility and cell permeability. CONCLUSION: Enumeration might be applicable in improving bioavailability, which could lead to the oral formulation of the Amphotericin B drug.

Flavonoids as promising anticancer agents: an in silico investigation of ADMET, binding affinity by molecular docking and molecular dynamics simulations.

Cancer is one of the most concerning diseases to humankind. Various treatment strategies are being employed for its treatment, out of which use of natural products is an essential one. Flavonoids have proven to be promising anticancer targets since decades. Also, tubulin is a significant biological target for the development of anticancer agents due to its crucial role in mitosis and abundance throughout the body. In the current study, in silico ADMET parameters of 104 flavonoids were examined, followed by molecular docking with the colchicine binding site of Tubulin protein (PDB; Id 4O2B). The best conformation from each flavonoid subcategory with the best docking score (MolDock score) was further subjected to 100 ns of molecular dynamics to investigate the protein-ligand complex's stability. Different parameters such as RMSD, RMSF, rGy and SASA were calculated for the six flavonoids using molecular dynamic studies. The top most compound from all the six subcategories of flavonoids elicited best behavior in the colchicine binding site of Tubulin protein. This in silico study employing molecular docking and molecular dynamics simulation provides strong evidence for flavonoids to be excellent anti-tubulin agents for the treatment of cancer.Communicated by Ramaswamy H. Sarma.

Correction: Pd-Catalysed [3 + 2]-cycloaddition towards the generation of bioactive bis-heterocycles/identification of COX-2 inhibitors via in silico analysis.

Correction for 'Pd-Catalysed [3 + 2]-cycloaddition towards the generation of bioactive bis-heterocycles/identification of COX-2 inhibitors via in silico analysis' by Elagandhula Sathish et al., Org. Biomol. Chem., 2022, 20, 4746-4752, https://doi.org/10.1039/D2OB00467D.

Heteroarylation of Congested α-Bromoamides with Imidazo-Heteroarenes and Indolizines via Aza-Oxyallyl Cations: Enroute to Dibenzoazepinone and Zolpidem Analogues.

Herein, we report a highly efficient and unprecedented approach for heteroarylation of congested α-bromoamides via electrophilic aromatic substitution of imidazo-heteroarenes and indolizines under mild reaction conditions (room temperature, metal, and oxidant free). The participation of an in situ generated aza-oxyallyl cation as an alkylating agent is the hallmark of this transformation. The method was readily adapted to synthesize novel imidazo-heteroarene-fused dibenzoazepinone architectures of potential medicinal value.

Chemical and Physical Approaches for Improved Biopharmaceutical Activity of Amphotericin B: Current and Future Prospective.

Over the last 50 years, the number of patients with mycotic infections has gradually increased. Amphotericin-B is a gold-standard drug used in serious systemic fungal infections. However, limited solubility and permeability are challenging issues associated with Amphotericin-B. Chemical modification is one of the ways to get its broader applicability and improved physicochemical properties. The review article provides a comprehensive overview of the chemical modification approach for investigating the mechanism of action, biological activity, bioavailability, and toxicity of Amphotericin B. Further, several drug delivery approaches have also been utilized to provide better therapeutic outcomes. This gives an overview of chemical approaches for exploring various factors associated with Amphotericin B and information on its drug delivery approaches for improved biopharmaceutical outcomes.

Pd-Catalysed [3 + 2]-cycloaddition towards the generation of bioactive bis-heterocycles/identification of COX-2 inhibitors via in silico analysis.

In the current research, we envisaged the synthesis of bis-heterocycles containing the dihydroisoxazole ring by [3 + 2] cycloaddition of VECs (vinyl ethylene carbonates) and nitrile oxides, assisted by a Pd catalyst. Herein we explored hydroximoyl chlorides as versatile precursors for the in situ generation of nitrile oxides that were exploited to achieve the cycloaddition reaction on a vinyl group of VECs to generate bis-heterocycles. In silico-based studies of bis-heterocycles on the cyclooxygenase (COX) enzyme displayed selective COX-2 inhibition.

Design, synthesis and anticancer activity of 2-arylimidazo[1,2-a]pyridinyl-3-amines.

A series of imido-heterocycle compounds were designed, synthesized, characterized, and evaluated for the anticancer potential using breast (MCF-7 and MDA-MB-231), pancreatic (PANC-1), and colon (HCT-116 and HT-29) cancer cell lines and normal cells, while normal cells showed no toxicity. Among the screened compounds, 4h exhibited the best anticancer potential with IC50 values ranging from 1 to 5.5 µM. Compound 4h caused G2/M phase arrest and apoptosis in all the cell lines except MDA-MB-231 mammosphere formation was inhibited. In-vitro enzyme assay showed selective topoisomerase IIα inhibition by compound 4h, leading to DNA damage as observed by fluorescent staining. Cell signalling studies showed decreased expression of cell cycle promoting related proteins while apoptotic proteins were upregulated. Interestingly MDA-MB-231 cells showed only cytostatic effects upon treatment with compound 4h due to defective p53 status. Toxicity study using overexpression of dominant-negative mutant p53 in MCF-7 cells (which have wild type functional p53) showed that anticancer potential of compound 4h is positively correlated with p53 expression.

E-pharmacophore guided discovery of pyrazolo[1,5-c]quinazolines as dual inhibitors of topoisomerase-I and histone deacetylase.

In the quest to ameliorate the camptothecin (CPT) downsides, we expedite to search for stable non-CPT analogues among 11 motifs of pyrazoloquinazolines reported. E-pharmacophore drug design approach helped filtering out pyrazolo[1,5-c]quinazolines as Topoisomerase I (TopoI) 'interfacial' inhibitors. Three compounds, 3c, 3e, and 3l were shown to be potent non-intercalating inhibitors of TopoI specifically and showed cancer cell-specific cytotoxicity in lung, breast and colon cancer cell lines. The compounds induced cell cycle arrest at S-phase, mitochondrial cell death pathway and modulated oxidative stress in cancer cells. Furthermore, a preliminary study was conducted to explore the feasibility of these compounds to be developed as dual TopoI-HDAC1 (histone deacetylase 1) inhibitors (4a) to combat resistance. Compound 4a was found to possess dual inhibitory capabilities in-vitro. Cytotoxic potential of 4a was found to be significantly higher than parent compound in 2D as well as 3D cancer cell models. Probable binding modes of 4a with TopoI and HDAC1 active sites were examined by molecular modelling.

An unprecedented N- to C-sulfonyl migration in the reaction of azomethine amine and allenoates: access to arylsulfonylmethyl substituted pyrazolo[1,5-c]quinazoline and mechanistic studies.

A serendipitous discovery of [1,3]-sulfonyl migration has been made in the two-component reaction of azomethine imine and allenoates. Current methodology involving N-S bond cleavage and C-S bond formation provided easy access to biologically important arylsulfonylmethyl substituted pyrazolo[1,5-c]quinazolines. Subsequently, a one-pot sequential protocol has been developed from the easily available starting material. The mechanistic investigation using quantum chemical methods revealed that the sulfonyl migration step is a concerted [1,3]-sigmatropic shift.

Exploration of Pd-catalysed four-component tandem reaction for one-pot assembly of pyrazolo[1,5-c]quinazolines as potential EGFR inhibitors.

A series of pyrazolo[1,5-c]quinazolines as EGFR inhibitors was designed and synthesized by highly efficient and novel multicomponent route involving Pd-catalyzed tandem one-pot four-component reaction. The reaction proceeds with good functional group tolerance under a simple condition with excellent regioselectivity and high efficiency. Target compounds were screened against cancer cell lines MDA-MB-231, A549 and H1299. Of these, 9b and 10b exhibited superior anticancer activity (IC50 < 2.5 µM) to erlotinib and gefitinib. Synthetics were able to inhibit EGFR mediated kinase activity, induced ROS in cancer cells promoting mitochondrial mediated apoptosis via halting cell cycle progression at G1 phase.

Pd-Catalyzed Four-Component Sequential Reaction Delivers a Modular Fluorophore Platform for Cell Imaging.

A Pd-catalyzed cascade reaction of four versatile privileged synthons is described. The sequential reaction involves the formation of five new chemical bonds by concatenating three distinct chemical steps. One of the derivatives exhibited absorption in the visible region, fluorescence with a high quantum yield, and excellent photostability. Its application is explored in live cell imaging, which exhibited cytoplasmic and mitochondrial specific staining with no toxicity.

Synthesis of quinazoline-3-oxides via a Pd(ii) catalyzed azide-isocyanide coupling/cyclocondensation reaction.

A novel and efficient protocol concerning palladium catalyzing the three-component reaction of 2-azidobenzaldehyde, isocyanide, and hydroxylamine hydrochloride is developed. This method allows the rapid elaboration of quinazoline 3-oxides in a one-pot fashion. The 3-CR mainly involves concatenation of azide-isocyanide denitrogenative coupling, condensation with hydroxylamine and 6-exo-dig cyclization. The salient features of the methodology are operational simplicity, use of milder reaction conditions, being devoid of any additives such as oxidants (redox neutral) or base, and releasing N2 and H2O as the byproducts.

Iodine-catalyzed cross-coupling of isocyanides and thiols for the synthesis of S-thiocarbamates.

A novel and efficient metal free, redox-neutral method for the synthesis of secondary thiocarbamates by cross-coupling of readily available thiophenol and isocyanides has been developed. The present methodology exhibits a broad substrate scope with good to excellent yields without an additive/extra oxidant under mild reaction conditions catalyzed by inexpensive iodine as the catalyst.

Relay tricyclic Pd(ii)/Ag(i) catalysis: design of a four-component reaction driven by nitrene-transfer on isocyanide yields inhibitors of EGFR.

Synthesis of pyrazolo[1,5-c]quinazolines from four easily available precursors is presented through a one-pot tricyclic Pd(ii)/Ag(i) relay catalysis. The bimetallic relay cascade forges five new chemical bonds by concatenating six discrete chemical steps. The relay catalysis enables four-component assembly of pyrazolo[1,5-c]quinazolines that selectively inhibit EGFR, exhibit apoptosis through the ROS-induced mitochondrial-mediated pathway, and arrest the cell cycle at the G1 phase.

Sequential Pd(0)/Fe(III) Catalyzed Azide-Isocyanide Coupling/Cyclization Reaction: One-Pot Synthesis of Aminotetrazoles.

A rapid and efficient synthesis of aminotetrazole from aryl azides, isocyanides, and TMSN3 is developed. The reaction is promoted by sequential Pd(0)/Fe(III) catalysis. The reaction sequence utilizes the Pd-catalyzed azide-isocyanide denitrogenative coupling reaction to generate unsymmetric carbodiimide in situ, which reacts with TMSN3 in the presence of FeCl3 in a single pot. The methodology has distinct advantages over traditional synthetic approaches where toxic Hg and Pb salts are employed at stoichiometric scale.

Ruthenium Catalyzed Intramolecular C-S Coupling Reactions: Synthetic Scope and Mechanistic Insight.

A ruthenium catalyzed intramolecular C-S coupling reaction of N-arylthioureas for the synthesis of 2-aminobenzothiazoles has been developed. Kinetic, isotope labeling, and computational studies reveal the involvement of an electrophilic ruthenation pathway instead of a direct C-H activation. Stereoelectronic effect of meta-substituents on the N-arylthiourea dictates the final regioselective outcome of the reaction.

Mild and efficient cyanuric chloride catalyzed Pictet-Spengler reaction.

A practical, mild and efficient protocol for the Pictet-Spengler reaction catalyzed by cyanuric chloride (trichloro-1,3,5-triazine, TCT) is described. The 6-endo cyclization of tryptophan/tryptamine and modified Pictet-Spengler substrates with both electron-withdrawing and electron-donating aldehydes was carried out by using a catalytic amount of TCT (10 mol %) in DMSO under a nitrogen atmosphere. TCT catalyzed the Pictet-Spengler reaction involving electron-donating aldehydes in excellent yield. Thus, it has a distinct advantage over the existing methodologies where electron-donating aldehydes failed to undergo 6-endo cyclization. Our methodology provided broad substrate scope and diversity. This is indeed the first report of the use of TCT as a catalyst for the Pictet-Spengler reaction.

Synthesis of novel N-rich polycyclic skeletons based on azoles and pyridines.

An efficient method for the synthesis of new polycyclic skeletons: triaza-benzofluorenes and triaza-pentalenonaphthalene from bicyclic privileged structures imidazopyridine and imidazothiazole, respectively, has been described using the Pictet-Spengler cyclization.