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A diastereoselective synthesis for the preparation of (R)‐methyl pipecolate and dextro‐erythrophacetoperane, analogs of methylphenidate, drugs used to treat attention deficit hyperactivity disorder, is reported. The key steps involve a high diastereoselective ring‐closing reaction via enolate formation and a diastereoselective ketone reduction reaction. The total synthesis of these valuable drugs could be obtained in only 5 and 8 steps, respectively, starting from (S)‐(−)‐methyl benzylamine. [ABSTRACT FROM AUTHOR]

Bis‐heterocycles were synthesized via a consecutive one‐pot process by a Groebke‐Blackburn‐Bienaymé reaction (GBB‐3CR) followed by Copper‐catalyzed Alkyne‐Azide Cycloaddition (CuAAC) assisted by alternative sustainable energies (ASE) such as ultrasonic and mechanical. These efficient and convergent strategies allowed the in situ generation of complex azides functionalized with imidazo[1,2‐a]pyridines (IMPs), which was used as a synthetic platform. The target molecules contain two privileged scaffolds in medicinal chemistry: IMPs and the heterocyclic bioisostere of trans‐amide bond, the 1,4‐disubstituted 1H‐1,2,3‐triazoles (1,4‐DS‐1,2,3‐Ts). [ABSTRACT FROM AUTHOR]

(R)-3-Isobutylglutarate monoamide (R-IBM) is a key intermediate in the synthesis of the analgesic drug pregabalin. Recently, the imidase BpIH derived from Burkholderia phytofirmans was identified as a promising catalyst for the industrial production of R-IBM. Notably, this catalyst has the distinct advantage of achieving a 100% theoretical yield from 3-isobutyl glutarimide (IBI). In this study, homology modeling and structure alignment techniques were used to determine the substrate binding pocket of BpIH. Semi-rational design was used to analyze the amino acid residue conservation in the binding pocket region of BpIH. Interestingly, mutations of several low-conserved amino acid located 6–9 Å from the substrate significantly enhanced the catalytic activity of BpIH. Among them, the triple mutant Y37FH133NS226I (YHS-I) showed approximately a fivefold increase in enzyme activity and a significantly improved catalytic efficiency (kcat/Km). Under the same reaction time and conditions, YHS-I successfully converted IBI into R-IBM with a conversion rate of 88.87%, with an enantiomeric excess (ee) of the product exceeding 99.9%. In comparison, wild-type BpIH had a conversion rate of only 38.15%. Molecular dynamics and docking results indicated that YHS-I had higher rigidity around the mutation sites. The synergistic substitutions of Y37F, H133N, and S226I altered the interaction network within the mutation site, enhancing the protein's affinity for the substrate and improving catalytic efficiency. Key points: • 100% theoretical yield of R-IBM by BpIH compared with 50% by resolution • Semi-rational design of BpIH based on conservativity with homologous enzymes • Mutant with enzyme activity of sixfold and product ee value of 99.9% [ABSTRACT FROM AUTHOR]

The photochemistry of EDA complexes is initiated from a groundstate associate with a biomolecule capable of intermolecular electron transfer by channelling chemical synthesis via a specific radical-based mechanistic pathway. Herein, we activate the innovative cascade mode of EDA complex photoexcitation for nitroreduction in aqueous media using charge transfer interactions between a sole donor and multiple acceptors (ArNO2, ArNO, and ArNHOH·glycine adduct). A triplet-state quenching experiment, UV-vis analysis, NMR titration, and preliminary kinetic investigation verified the rationality and feasibility of the mechanism. With successful applications of this cascaded system in arylamine compounds and commercially available drug synthesis (61 examples), these achievements highlight the attractiveness, usefulness, and effectiveness of this protocol. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Unsymmetrical diarylamines are crucial components in many pharmaceuticals and functional materials. In this study, we introduce an efficient Chan‐Lam cross‐coupling method that utilizes phenylboronic acids and aryl azides as coupling agents in a redox‐neutral environment, enabled by a synergistic nickel/photoredox catalytic system. This approach leverages a proton‐coupled electron transfer mechanism to bypass the typical nitrene pathway associated with aryl azides, which is prone to intramolecular rearrangement, C—H amination, and reductive hydrogenation. Notably, our method exhibits broad compatibility with a variety of functional groups, including those derived from pharmaceuticals, demonstrating its versatile potential in organic synthesis and drug modification. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: In this paper, the difunctionalizative perfluoroalkyloximation of alkenes has been developed for the first time. This photochemical method allows for the synthesis of various perfluoroalkyl ethanone oximes with excellent regioselectivity and good functional group tolerance. Our method employs the most common perfluoroalkyl source, perfluoroalkyl iodides, as Rf reagents. Besides long‐chain perfluoroalkyl groups, this approach could be extended to incorporating additional groups, including trifluoromethyl, difluoromethyl, sulfonyl, and malonate, selectively into olefins, resulting in a range of β‐substituted ethanone oximes. Notably, the potential of this method in the Fukuyama indole synthesis, generating novel 2‐perfluoroalkylated 3‐(α‐oximidobenzyl)indoles via a radical cascade mechanism with 2‐vinylphenylacryloyl isocyanate as the radical acceptor, presents a compelling avenue for drug synthesis. The protocol is efficient, scalable, and useful for late‐stage modification of bioactive molecules. [ABSTRACT FROM AUTHOR]

Atropisomers have attracted a great deal of attention lately due to their numerous applications in organic synthesis and to their employment in drug discovery. However, the synthetic arsenal at our disposal with which to access them remains limited. The research described herein is two‐pronged; we both demonstrate the use of MCR chemistry as a synthetic strategy for the de novo synthesis of a class of atropisomers having high barriers to rotation with the simultaneous insertion of multiple chiral elements and we study these unprecedented molecular systems by employing a combination of crystallography, NMR and DFT calculations. By fully exploiting the synthetic capabilities of our chemistry, we have been able to monitor a range of different types of interaction, i. e. π‐π, CH–π, heteroatom‐π and CD–π, in order to conduct structure‐property studies. The results could be applied both to atroposelective synthesis and in drug discovery. [ABSTRACT FROM AUTHOR]

Potential genotoxic impurities in medications are an increasing concern in the pharmaceutical industry and regulatory bodies because of the risk of human carcinogenesis. To prevent the emergence of these impurities, it is crucial to carefully examine not only the final product but also the intermediates and key starting material (KSM) used in drug synthesis. During the related substances analysis of KSM of Famotidine, an unknown impurity in the range of 0.5–1.0% was found prompting the need for isolation and characterization due to the possibility of its to infiltrate into the final product. In this study, the impurity was isolated and characterized as 5-(2-chloroethyl)-3,3-dimethyl-3,4-dihydro-2H-1,2,4,6-thiatriazine 1,1-dioxide using multiple instrumental analysis, uncovering a structural alert that raises concern. Considering the potential impact of impurity on human health, an in silico genotoxicity assessment was established using Derek and Sarah tool in accordance with ICH M7 guideline. Furthermore, molecular docking and molecular dynamics simulation were performed to evaluate the specific interaction of the impurity with DNA. The findings reveal consistent interaction of the impurity with the dG-rich region of the DNA duplex and binding at the minor groove. Both in silico prediction and molecular dynamic study confirmed the genotoxic character of the impurity. The newly discovered impurity in famotidine has not been reported previously, and there is currently no analytical method available for its identification and control. A highly sensitive HPLC-UV method was developed and validated in accordance with ICH requirements, enabling quantification of the impurity at trace level in famotidine ensuring its safe release. [ABSTRACT FROM AUTHOR]

Some antibiotics that are frequently employed are β-lactams. In light of the hydrolytic process of β-lactamase, found in Gram-negative bacteria, inhibitors of β-lactamase (BLIs) have been produced. Examples of first-generation β-lactamase inhibitors include sulbactam, clavulanic acid, and tazobactam. Many kinds of bacteria immune to inhibitors have appeared, and none cover all the β-lactamase classes. Various methods have been utilized to develop second-generation β-lactamase inhibitors possessing new structures and facilitate the formation of diazabicyclooctane (DBO), cyclic boronate, metallo-, and dual-nature β-lactamase inhibitors. This review describes numerous promising second-generation β-lactamase inhibitors, including vaborbactam, avibactam, and cyclic boronate serine-β-lactamase inhibitors. Furthermore, it covers developments and methods for synthesizing MβL (metallo-β-lactamase inhibitors), which are clinically effective, as well as the various dual-nature-based inhibitors of β-lactamases that have been developed. Several combinations are still only used in preclinical or clinical research, although only a few are currently used in clinics. This review comprises materials on the research progress of BLIs over the last five years. It highlights the ongoing need to produce new and unique BLIs to counter the appearance of multidrug-resistant bacteria. At present, second-generation BLIs represent an efficient and successful strategy. [ABSTRACT FROM AUTHOR]

An improved, scalable, industrially feasible telescopic process for multigram synthesis of highly commercialized antidepressant drug, moclobemide has been developed. Unlike the conventional approaches, this process enjoys the privilege of being an economical, operationally simple, effectively scalable, and quantitative method for the synthesis of amide‐containing drug moclobemide, showcasing easy isolation and purification without the aid of column chromatography. An environmentally benign reagent combination of TBN and NHS very effectively converts the acyl source, 4‐chlorobenzaldehyde into its N‐hydroxysuccinimide ester intermediate, which simply affords the drug molecule after nucleophilic substitution with the amine source. The synthetic process has successfully been scaled‐up upto ~145 g scale with 75 % overall yield and >95 % first crop HPLC purity. [ABSTRACT FROM AUTHOR]

Nucleoside phosphorylases (NPs) are pivotal enzymes in the salvage pathway, catalyzing the reversible phosphorolysis of nucleosides to produce nucleobases and α-D-ribose 1-phosphate. Due to their efficiency in catalyzing nucleoside synthesis from purine or pyrimidine bases, these enzymes hold significant industrial importance in the production of nucleoside-based drugs. Given that the thermodynamic equilibrium for purine NPs (PNPs) is favorable for nucleoside synthesis—unlike pyrimidine NPs (PyNPs, UP, and TP)—multi-enzymatic systems combining PNPs with PyNPs, UPs, or TPs are commonly employed in the synthesis of nucleoside analogs. In this study, we report the first development of two engineered bifunctional fusion enzymes, created through the genetic fusion of purine nucleoside phosphorylase I (PNP I) and thymidine phosphorylase (TP) from Thermus thermophilus. These fusion constructs, PNP I/TP-His and TP/PNP I-His, provide an innovative one-pot, single-step alternative to traditional multi-enzymatic synthesis approaches. Interestingly, both fusion enzymes retain phosphorolytic activity for both purine and pyrimidine nucleosides, demonstrating significant activity at elevated temperatures (60–90 °C) and within a pH range of 6–8. Additionally, both enzymes exhibit high thermal stability, maintaining approximately 80–100% of their activity when incubated at 60–80 °C over extended periods. Furthermore, the transglycosylation capabilities of the fusion enzymes were explored, demonstrating successful catalysis between purine (2′-deoxy)ribonucleosides and pyrimidine bases, and vice versa. To optimize reaction conditions, the effects of pH and temperature on transglycosylation activity were systematically examined. Finally, as a proof of concept, these fusion enzymes were successfully employed in the synthesis of various purine and pyrimidine ribonucleoside and 2′-deoxyribonucleoside analogs, underscoring their potential as versatile biocatalysts in nucleoside-based drug synthesis. [ABSTRACT FROM AUTHOR]

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Sulfinamidines are promising aza‐SIV chiral building blocks in asymmetric synthesis and drug discovery. However, no report has documented their enantioselective synthesis. Here we present an enantioselective synthesis of sulfinamidines via electrophilic amination of sulfenamides using an enantiopure N−H oxaziridine. The resulting enantiomerically enriched primary sulfinamidines are configurationally stable at 90 °C in solution and show remarkable stability against organic acids and bases under non‐aqueous conditions. We also demonstrate a one‐pot, three‐component, enantioselective synthesis of sulfinamides using N−H oxaziridine reagents. [ABSTRACT FROM AUTHOR]

In this communication, we designed a highly selective camphor sulfonyl functionalized crown-ether-tethered calix[4]arene-derived organocatalyst for asymmetric Strecker reaction to provide the desired cyano adducts in high yields (∼99.9% yield) and enantioselectivities (up to 99.3% ee). Furthermore, 2 step facile syntheses of the antiplatelet drug (S)-clopidogrel exemplify the potential of this method for the preparation of commercial compounds. [ABSTRACT FROM AUTHOR]

The reagent system based on the combined use of Et3SiH/I2 acts as an efficient N-glycosidation promoter for the synthesis of natural and sugar-modified nucleosides. An analysis of reaction stereoselectivity in the absence of C2-positioned stereodirecting groups revealed high selectivity with six-membered substrates, depending on the nucleophilic character of the nucleobase or based on anomerization reactions. The synthetic utility of the Et3SiH/I2-mediated N-glycosidation reaction was highlighted by its use in the synthesis of the investigational drug apricitabine. [ABSTRACT FROM AUTHOR]

During gliotoxin biosynthesis in fungi, the cytochrome P450 GliF enzyme catalyzes an unusual C–N ring-closure step while also an aromatic ring is hydroxylated in the same reaction cycle, which may have relevance to drug synthesis reactions in biotechnology. However, as the details of the reaction mechanism are still controversial, no applications have been developed yet. To resolve the mechanism of gliotoxin biosynthesis and gain insight into the steps leading to ring-closure, we ran a combination of molecular dynamics and density functional theory calculations on the structure and reactivity of P450 GliF and tested a range of possible reaction mechanisms, pathways and models. The calculations show that, rather than hydrogen atom transfer from the substrate to Compound I, an initial proton transfer transition state is followed by a fast electron transfer en route to the radical intermediate, and hence a non-synchronous hydrogen atom abstraction takes place. The radical intermediate then reacts by OH rebound to the aromatic ring to form a biradical in the substrate that, through ring-closure between the radical centers, gives gliotoxin products. Interestingly, the structure and energetics of the reaction mechanisms appear little affected by the addition of polar groups to the model and hence we predict that the reaction can be catalyzed by other P450 isozymes that also bind the same substrate. Alternative pathways, such as a pathway starting with an electrophilic attack on the arene to form an epoxide, are high in energy and are ruled out. [ABSTRACT FROM AUTHOR]

Phenolic compounds have long captivated the interest of organic synthesis, particularly in their quest for selective hydroxylation of arenes using H2O as a hydroxyl source. However, the inherent high reactivity and low redox potential of phenols often lead to undesirable overoxidation byproducts. To address this challenge, herein, we develop an electrophotochemical approach, finetuning substrate oxidative potential and enabling para-selective hydroxylation of anilides. This method showcases versatility, accommodating a wide array of substrates, while revealing high regional selectivity and compatibility with diverse functional groups. Moreover, the protocol allows facile late-stage functionalization of biologically active molecules. Mechanistic investigations demonstrate the activation of anilides by the excited state photocatalyst, effectively decreasing their oxidative potential and enhancing regional selectivity during hydroxylation. By using this protocol, important drug molecules such as Paracetamol, Fenretinide, Practolol, and AM404 could be synthesized, demonstrating the applicability of this approach in drug synthesis and late-stage functionalization. Phenolic compounds have long captivated the interest of organic synthesis, particularly in their quest for selective hydroxylation of arenes using H2O as a hydroxyl source but the inherent high reactivity and low redox potential of phenols often lead to undesirable overoxidation byproducts. Here the authors develop an electrophotochemical approach, finetuning substrate oxidative potential and enabling para-selective hydroxylation of anilides. [ABSTRACT FROM AUTHOR]

A green, efficient and highly regioselective synthesis of flavonoids and their derivatives from β-phenoxyl ynones using wet 1,3-propanediol as reaction medium was developed, without any metal catalysts, bases, acids or additives. The reaction shows a high level of functional tolerance and a broad substrate scope, with simple operation and high atomic economy. Furthermore, a mechanism study has shown that 1,3-propanediol acts both as a participant and solvent to achieve regioselective cyclization and carbonyl site oxygen migration. Significantly, the total synthesis of drug molecules efloxate 6 and flavodilol 7 and bioactive molecules, such as 8 and MN-64, further demonstrates the efficacy and synthetic potential of this method. Moreover, most established flavonoid derivatives are found to have strong anti-inflammatory activities, during which 2d exhibits a better result with lower IC50 value of 5.67 μg mL−1. [ABSTRACT FROM AUTHOR]

The reduction of aromatic compounds constitutes a fundamental and ongoing area of investigation. The selective reduction of polycyclic aromatic compounds to give either fully or partially reduced products remains a challenge, especially in applications to complex molecules at scale. Herein, we present a selective electrochemical hydrogenation of polycyclic arenes conducted under mild conditions. A noteworthy achievement of this approach is the ability to finely control both the complete and partial reduction of specific aromatic rings within polycyclic arenes by judiciously varying the reaction solvents. Mechanistic investigations elucidate the pivotal role played by in situ proton generation and interface regulation in governing reaction selectivity. The reductive electrochemical conditions show a very high level of functional‐group tolerance. Furthermore, this methodology represents an easily scalable reduction (demonstrated by the reduction of 1 kg scale starting material) using electrochemical flow chemistry to give key intermediates for the synthesis of specific drugs. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Herein, we present a method for the homogeneous hydrogenation of nitroarenes to produce anilines using low catalyst loading (1 mo%) of copper N‐heterocyclic carbene complexes as the catalyst and ammonia borane as the source of hydrogen. A wide range of nitroarenes, featuring diverse functional groups, were selectively transformed into their corresponding primary aromatic amines with high yields. This process can be readily scaled up and exhibits compatibility with various sensitive functional groups, including halogen, trifluoromethyl, aminomethyl, alkenyl, cyano, ester, amide, and hydroxyl. Notably, this catalytic methodology finds application in the synthesis of essential drug compounds. Mechanistic investigations suggest that the in‐situ‐generated Cu‐H species may serve as active intermediates, with reduction pathways involving species such as azobenzene, 1,2‐diphenylhydrazine, nitrosobenzene, and N‐phenylhydroxylamine. [ABSTRACT FROM AUTHOR]

Infections with Flaviviridae viruses, such as hepatitis C (HCV), dengue (DENV), and yellow fever (YFV) viruses, are major public health problems worldwide. In the case of HCV, treatment is associated with drug resistance and high costs, while there is no clinically approved therapy for DENV and YFV. Consequently, there is still a need for new chemotherapies with alternative modes of action. We have previously identified novel 2-hydroxypyrazino[1,2-a]indole-1,3(2H,4H)-diones as metal-chelating inhibitors targeting HCV RNA replication. Here, by utilizing a structure-based approach, we rationally designed a second series of compounds by introducing various substituents at the indole core structure and at the imidic nitrogen, to improve specificity against the RNA-dependent RNA polymerase (RdRp). The resulting derivatives were evaluated for their potency against HCV genotype 1b, DENV2, and YFV-17D using stable replicon cell lines. The most favorable substitution was nitro at position 6 of the indole ring (compound 36), conferring EC50 1.6 μM against HCV 1b and 2.57 μΜ against HCV 1a, with a high selectivity index. Compound 52, carrying the acetohydroxamic acid functionality (-CH2CONHOH) on the imidic nitrogen, and compound 78, the methyl-substituted molecule at the position 4 indolediketopiperazine counterpart, were the most effective against DENV and YFV, respectively. Interestingly, compound 36 had a high genetic barrier to resistance and only one resistance mutation was detected, T181I in NS5B, suggesting that the compound target HCV RdRp is in accordance with our predicted model. [ABSTRACT FROM AUTHOR]

Human liver subcellular fractions, including liver microsomes (HLM), liver cytosol fractions, and S9 fractions, are extensively utilized in in vitro assays to predict liver metabolism. The S9 fractions are supernatants of human liver homogenates that contain both microsomes and cytosol, which include most cytochrome P450 (CYP) enzymes and soluble phase II enzymes such as glucuronosyltransferases and sulfotransferases. This study reports on the direct electrochemistry and biocatalytic features of redox-active enzymes in S9 fractions for the first time. We investigated the electrochemical properties of S9 films by immobilizing them onto a high-purity graphite (HPG) electrode and performing cyclic voltammetry under anaerobic (Ar-saturated) and aerobic (O2-saturated) conditions. The heterogeneous electron transfer rate between the S9 film and the HPG electrode was found to be 14 ± 3 s−1, with a formal potential of −0.451 V vs. Ag/AgCl reference electrode, which confirmed the electrochemical activation of the FAD/FMN cofactor containing CYP450-reductase (CPR) as the electron receiver from the electrode. The S9 films have also demonstrated catalytic oxygen reduction under aerobic conditions, identical to HLM films attached to similar electrodes. Additionally, we investigated CYP activity in the S9 biofilm for phase I metabolism using diclofenac hydroxylation as a probe reaction and identified metabolic products using liquid chromatography–mass spectrometry (LC-MS). Investigating the feasibility of utilizing liver S9 fractions in such electrochemical assays offers significant advantages for pharmacological and toxicological evaluations of new drugs in development while providing valuable insights for the development of efficient biosensor and bioreactor platforms. [ABSTRACT FROM AUTHOR]

This study explores the medicinal potential of Pergularia daemia, a perennial vine abundant along Indian roadsides, focusing on its leaves have diverse therapeutic properties in traditional medicine. This research investigates its unexplored potential in application of drug delivery and the synthesis of zinc oxide nano-particles from its leaves. PD mediated Zinc Oxide nanoparticles were synthesized by precipitate method. The qualitative phyto chemical analysis of PD leaves extract was carried out and the extract showed the presence of carbohydrates, phenols, flavanoids, alkaloids and terpenoids. The synthesized zinc oxide nanoparticles were characterized by UV–Visible spectroscopy, Fourier transform Infrared spectroscopy, X-ray diffraction Analysis and scanning electron microscope. The results from characterization suggest that the synthesized compound was ZnO in nano scale which was in oval shape and with high purity. The synthesized zinc oxide nano particle could be a huge application in medical field, pharmaceutical and biotechnology in near future. [ABSTRACT FROM AUTHOR]

Novel biocompatible systems suitable for the controlled release of active ingredients are under the spotlight within the last few years. The present investigation focuses on the preparation of nanoparticles (NPs) based on the amphiphilic copolymer pullulan‐graft‐poly(Z‐L‐lysine) bearing different amounts of lysine (10, 20, and 30 wt%), and on the evaluation of their ensuing viability to encapsulate the hydrophobic nonsteroidal anti‐inflammatory drug indomethacin (INDO). The copolymers are synthesized by ring‐opening polymerization, characterized by NMR and FTIR, and their critical aggregation concentration is determined by fluorescence. The NPs are prepared with and without INDO using different copolymer/solvent ratios and INDO/copolymer ratios. The hydrodynamic diameter and polydispersity of the NP suspensions are monitored by dynamic light scattering for 30 days. Their sizes vary between 208 and 338 nm, and some reach the micrometric range (19–73 μm). INDO‐free NPs are identified as spherical‐shaped by atomic force microscopy. Two formulations are tested in terms of encapsulation efficiency (EE = 43%–89%), and the drug crystallinity (DC = 7%–27%) which is determined by differential scanning calorimetry, indicating a reduction with respect to pristine INDO. The results suggest that the copolymers prepared herewith have potential to be applied as carriers for new drug delivery systems of class II drugs. [ABSTRACT FROM AUTHOR]

Alkylamine structures represent one of the most functional and widely used in organic synthesis and drug design. However, the general methods for the functionalization of the shielded and deshielded alkyl radicals remain elusive. Here, we report a general deoxygenative amination protocol using alcohol-derived carbazates and nitrobenzene under electrochemical conditions. A range of primary, secondary, and tertiary alkylamines are obtained. This practical procedure can be scaled up through electrochemical continuous flow technique. Secondary arylalkylamines represent important building blocks for organic synthesis, and as such their straightforward synthesis from readily available chemicals remains a priority in organic chemistry. Here, the authors report a synthesis of arylalkylamines from nitroarenes and carbazates via paired electrolysis. [ABSTRACT FROM AUTHOR]

The beginning of photochemical reactions revolutionized synthetic chemistry through sustainable practices. This review explores cutting‐edge developments in leveraging light‐induced processes for generating cascaded C−C and C‐hetero bonds without catalysts. Significantly, catalyst‐free photoinduced methodologies have garnered considerable attention, especially in the creation of varied heterocyclic frameworks for drug design and the synthesis of natural products. The article delves into underlying mechanisms, addresses limitations, and evaluates various methodologies, emphasizing the potential of photocatalyst and transition metal‐free photochemical reactions to enhance sustainability. Divided into two sections, it covers recent strides in C−C and C‐heteroatom and multiple C‐heteroatom bond formation reactions. [ABSTRACT FROM AUTHOR]

Bilastine (BLA), 2-(4-(2-(4-(1-(2-ethoxyethyl)-1H-benzo[d]imidazole-2-yl)-piperidin-1-yl)-ethyl)-phenyl)-2-methylpropanoic acid, is an active antihistamine drug. With the idea of repurposing drugs from the existing pool of 'active' pharmaceutical ingredients, the therapeutic potency of bilastine as an anticancer agent was investigated via the tailored synthesis of a metal-based anticancer drug formulation of the type [BLA(phen)2M(II)]+·X−, where M = Co, Cu, and Zn and X− = NO3 and ClO4. The synthesized metal-based chemotherapeutics derived from the bilastine drug that acts as a ligand were thoroughly characterized using spectroscopic techniques, namely, UV-vis, FT-IR, and EPR (in the case of 1 and 2); 1H-NMR and 13C-NMR (in the case of 3); ESI-MS and single-crystal X-ray diffraction studies. Comprehensive biological studies (DNA binding, cleavage, and cytotoxic activity) using various biophysical and gel electrophoretic methods were carried out to validate their potential as anticancer agents. The cytotoxic activity of 'therapeutically promising' copper(II)-based drug candidate 2 was evaluated against MCF-7, MBA-MD-231, HeLa, HepG2, and Mia-PaCa-2 cancer cells via an SRB assay, and the results demonstrated 2 as a potent anticancer agent at low nanomolar concentrations against all tested cancer cells, preferably with a much superior anticancer efficacy against human pancreatic cancer cells. [ABSTRACT FROM AUTHOR]

Multicomponent tandem reactions have become indispensable synthetic methods due to their economic advantages and efficient usage in natural products and drug synthesis. The emergence of metalated covalent organic frameworks (MCOFs) has opened up new opportunities for the advancement of multicomponent tandem reactions. In contrast to commonly used homogeneous transition metal catalysts, MCOFs possess regular porosity, high crystallinity, and rich metal chelation sites that facilitate the uniform distribution and anchoring of metals within their cavities. Thus, they show extremely high activity and have recently been widely employed as catalysts for multicomponent tandem reactions. It is timely to conduct a review of MCOFs in multicomponent tandem reactions, in order to offer guidance and assistance for the synthesis of MCOF catalysts and their application in multicomponent tandem reactions. This review provides a comprehensive overview of the design and synthesis of MCOFs, their application and progress in multicomponent tandem reactions, and the primary challenges encountered during their current development with the aim of contributing to the promotion of the field. [ABSTRACT FROM AUTHOR]

Dearomatization has emerged as a powerful tool for rapid construction of 3D molecular architectures from simple, abundant, and planar (hetero)arenes. The field has evolved beyond simple dearomatization driven by new synthetic technology development. With the renaissance of photocatalysis and expansion of the activation mode, the last few years have witnessed impressive developments in innovative photochemical dearomatization methodologies, enabling skeletal modifications of dearomatized structures. They offer truly efficient and useful tools for facile construction of highly complex structures, which are viable for natural product synthesis and drug discovery. In this review, we aim to provide a mechanistically insightful overview on these innovations based on the degree of skeletal alteration, categorized into dearomative functionalization and skeletal editing, and to highlight their synthetic utilities. [ABSTRACT FROM AUTHOR]

A one‐pot Pd‐catalyzed tandem process to prepare (2‐arylallyl) aryl sulfones has been developed. This strategy is based on the modular assembly of a boronic acid, a sodium sulfinate and 2‐bromoallyl acetate. The reaction is completely regioselective towards the terminal alkene, yielding (2‐arylallyl) aryl (or alkyl) sulfones with yields ranging from 56 to 93%. Control experiments together with DFT calculations allowed to propose a plausible reaction mechanism of the tandem reaction. The usefulness of this methodology has been demonstrated with the formal synthesis of the marketed drug Apremilast and of several natural products by asymmetric hydrogenation. Using the commercially available UbaPHOX iridium complex, chiral β‐methyl sulfones with up to 98% ee were obtained [ABSTRACT FROM AUTHOR]

Tempted by the unique medicinal and biological potential of indole‐containing heterocycles, chemists, especially those specializing in heterocycle synthesis and drug discovery, are actively pursuing their efficient construction. This review spotlights the latest advancements in microwave‐assisted (M. W.) synthesis of diverse indole‐based heterocyclic compounds. We systematically categorize the reported methods based on the specific indole substitution patterns. This review concise the microwave assisted synthesis of indole based‐pyridine derivatives, indole based‐pyrimidine, indole based‐oxindole, spiro‐oxindole, Fischer indole Heck‐isomerization derivatives, functionalized indole, substituted indoles, indolyl quinoline, indole triazole and indolylnicotinonitriles derivatives. Ultimately, this review aims to provide organic and medicinal chemists with a concise yet informative guide to recent methodologies employing indole derivatives in the microwave‐powered synthesis of heterocycles. [ABSTRACT FROM AUTHOR]

Atenolol, one of the top five best-selling drugs in the world today used to treat angina and hypertension, and to reduce the risk of death after a heart attack, faces challenges in current synthetic methods to address inefficiencies and environmental concerns. The traditional synthesis of this drug involves a process that generates a large amount of waste and other by-products that need disposal. This study presents a one-pot DES-based sustainable protocol for synthesizing atenolol. The use of the DES allowed the entire process to be conducted with no need for additional bases or catalysts, in short reaction times, under mild conditions, and avoiding chromatographic purification. The overall yield of atenolol was 95%. The scalability of the process to gram-scale production was successfully demonstrated, emphasizing its potential in industrial applications. Finally, the 'greenness' evaluation, performed using the First Pass CHEM21 Metrics Toolkit, highlighted the superiority in terms of the atom economy, the reaction mass efficiency, and the overall process mass intensity of the DES-based synthesis compared with the already existing methods. [ABSTRACT FROM AUTHOR]

Heteroatoms are very important in polyoxometalates (POMs) because they can lead to appealing architectures and unexpected properties in the final POMs. In this work, we elaborately designed and isolated three Silverton-type POMs ([UIVMo12O42] 8−) with UIV as the heteroatom and linked by FeII (FeUMo), CoII (CoUMo) and NiII (NiUMo). These Silverton-type U-containing polyoxomolybdates were demonstrated to be the first molecular catalysts for the synthesis of quinazolinone drug precursor skeletons. Under the optimized reaction conditions, 27 quinazolinones could be obtained in high yield with water as the sole by-product under mild conditions. Furthermore, NiUMo can be recycled seven times and still keep high stability and catalytic activity. [ABSTRACT FROM AUTHOR]

[Display omitted] Chemo-immunotherapy, in which chemotherapeutic drugs activate immune system to suppress tumor growth and metastases, has great potential for clinical application. However, insufficient immunogenic cell death and serious side effects caused by tumor multidrug resistance and non-specific drug distribution, as well as inadequate and dysfunctional immune cells, greatly impair the effectiveness of chemo-immunotherapy. Herein, taking advantage of the functional diversity and structural programmability of nucleic acids, a DNA-based bioorthogonal nanoagonist is constructed to initiate and augment immune responses for robust chemo-immunotherapy. Benefiting from polyvalent targeting and template effects of DNA, the tailor-made nanoagonist shows prior bioorthogonal catalytic performance. Chemotherapeutic drug is bioorthogonally synthesized in situ under the catalysis of the nanoagonist, maximizing immunogenic cell death and minimizing systemic toxicity. The large amount of antigen and damage-associated molecular patterns released from dying tumor cells effectively initiates antitumor immunity. Meanwhile, the integration of high density of immunologic adjuvant can more effectively stimulate immune cells. The combination of bioorthogonal catalytic drug synthesis and immunostimulatory effect of DNA adjuvant not only destroys local primary tumors, but also eliminates distal metastasis. Moreover, the nanoagonist triggered the immune memory effect. The work extends the application of bioorthogonal chemistry to immunotherapy and provides a safe and powerful strategy for cancer chemo-immunotherapy. [ABSTRACT FROM AUTHOR]

In this work, new substituted drugs polymerized as new homogenous polymers with study their medicinal properties to extend the controlled drug. The first step includes the preparation of compound N-(4-hydroxyphenyl) maleimide (D1) via a reaction of maleic anhydride with 4-aminophenol. Then compound (D1) was converted to maleimide phenol acetic acid ether (D2) which converted to its corresponding acyl chloride derivative which reacted with amino drugs (Ceftriaxone, Ciprofloxacin) afforded monomers (D3 and D4). Homogeneous polymers (D5 and D6) were prepared via free radical polymerization reaction of the monomers (D3, and D4) under nitrogen using Benzoyl peroxide (Bpo) as initiator. All these prepared monomers and polymers were characterized by FT-IR and 1H-NMR, 13C-NMR techniques and C.H.N.S. Study of the drug release behavior in acidic and basic media as well as the swelling ratio were achieved. The antibacterial activity and physical properties of all monomers and polymers were studied. [ABSTRACT FROM AUTHOR]

Graph neural networks have received increased attention over the past years due to their promising ability to handle graph-structured data, which can be found in many real-world problems such as recommender systems and drug synthesis. Most existing research focuses on using graph neural networks to solve homophilous problems, and not much attention has been paid to heterophily-type problems. In this paper, we propose a graph network model for graph coloring, which is a class of representative heterophilous problems. Different from the message passing in conventional graph networks, we introduce negative message passing into a physics-inspired graph neural network for more effective information exchange in handling graph coloring problems. Moreover, a new term in the objective function taking into account the information entropy of nodes is suggested to increase the uniformity of the color assignment of each node, giving the neural network more chance to choose suitable colors for each node. Therefore, it could avoid the final solution getting stuck into the local optimum. Experimental studies are carried out to compare the proposed graph model with five state-of-the-art algorithms on ten publicly available graph coloring problems and d-regular graphs with up to 10 4 nodes, demonstrating the effectiveness of the proposed graph neural network. [ABSTRACT FROM AUTHOR]

The pivotal role of electrochemistry has significantly improved the step economy of organic transformations, thereby surpassing conventional pathways. Sustainable electrochemical transformations enormously influenced the chemical synthesis and attracted significant attention towards pharmaceutical industries. More specifically, the electrochemical organic transformation streamlines the synthesis of a variety of drugs and precursors of drug-like molecules. This review summarised the electrochemical synthesis of more than 50 such drugs, therapeutic chemicals, pharmaceuticals, and precursors of drug-like molecules, which were directly or indirectly synthesised over the period of 2017–2023. [ABSTRACT FROM AUTHOR]

The classic chemical Mitsunobu reaction suffers from the need of excess alcohol activation reagents and the generation of significant by‐products. Efforts to overcome these limitations have resulted in numerous creative solutions, but the substrate scope of these catalytic processes remains limited. Here we report an electrochemical Mitsunobu‐type reaction, which features azo‐free alcohol activation and broad substrate scope. This user‐friendly technology allows a vast collection of heterocycles as the nucleophile, which can couple with a series of chiral cyclic and acyclic alcohols in moderate to high yields and excellent ee's. This practical reaction is scalable, chemoselective, uses simple Electrasyn setup with inexpensive electrodes and requires no precaution to exclude air and moisture. The synthetic utility is further demonstrated on the structural modification of diverse bioactive natural products and pharmaceutical derivatives and its straightforward application in a multiple‐step synthesis of a drug candidate. [ABSTRACT FROM AUTHOR]

Alcohol is ubiquitous with unparalleled structural diversity and thus has wide applications as a native functional group in organic synthesis. It is highly prevalent among biomolecules and offers promising opportunities for the development of chemical libraries. Over the last decade, alcohol has been extensively used as an environmentally friendly chemical for numerous organic transformations. In this review, we collectively discuss the utilisation of alcohol from 2015 to 2023 in various organic transformations and their application toward intermediates of drugs, drug derivatives and natural product-like molecules. Notable features discussed are as follows: (i) sustainable approaches for C–X alkylation (X = C, N, or O) including O-phosphorylation of alcohols, (ii) newer strategies using methanol as a methylating reagent, (iii) allylation of alkenes and alkynes including allylic trifluoromethylations, (iv) alkenylation of N-heterocycles, ketones, sulfones, and ylides towards the synthesis of drug-like molecules, (v) cyclisation and annulation to pharmaceutically active molecules, and (vi) coupling of alcohols with aryl halides or triflates, aryl cyanide and olefins to access drug-like molecules. We summarise the synthesis of over 100 drugs via several approaches, where alcohol was used as one of the potential coupling partners. Additionally, a library of molecules consisting over 60 fatty acids or steroid motifs is documented for late-stage functionalisation including the challenges and opportunities for harnessing alcohols as renewable resources. [ABSTRACT FROM AUTHOR]

In the realm of organic and green chemistry, the functionalization of cyclobutanes presents a significant challenge, given their unique structural properties and biological relevance. Particularly, the introduction of difluoromethyl groups into cyclobutane frameworks is a burgeoning area of interest due to their potential in drug design and synthesis. However, the construction of difluoromethyl cyclobutanes heavily relies on the environmentally burdensome fluorination of cyclobutyl ketones. Methods to efficiently and directly introduce difluoromethyl groups into cyclobutanes remain underexplored. This study introduces a novel photochemical protocol for the selective difluoromethylation or bromo difluoromethylation of bicyclobutanes, leveraging green solvent-controlled reactions. Remarkably, this method exhibits the merits of both green chemistry and organic chemistry such as renewable visible light as reaction power, high atom economy and fully controlled chemo-selectivity. This work also reveals the mechanism behind the remarkable selectivity achieved. Emphasizing the importance of difluoromethyl cyclobutane scaffolds as bioisosteres, this research not only broadens the chemical space in organic synthesis but also offers new avenues for pharmaceutical discovery. The findings demonstrate the robustness and versatility of the method, including its applicability to drug modifications, addressing a crucial gap in the green synthesis of complex medicinal molecules. [ABSTRACT FROM AUTHOR]

Stretching a segment of a polymer beyond its contour length makes its (primarily backbone) bonds more dissociatively labile, which enables polymer mechanochemistry. Integrating some backbone bonds into suitably designed molecular moieties yields mechanistically and kinetically diverse chemistry, which is becoming increasingly exploitable. Examples include, most prominently, attempts to improve mechanical properties of bulk polymers, as well as prospective applications in drug delivery and synthesis. This review aims to highlight an emerging effort to apply the concepts and experimental tools of mechanochemistry to fundamental physical questions in soft matter. A succinct summary of the state‐of‐the‐knowledge of the field, with emphasis on foundational concepts and generalizable observations, is followed by analysis of 3 recent examples of mechanochemistry yielding molecular‐level details of elastomer failure, macromolecular chain dynamics in elongational flows and kinetic allostery. We conclude with reasons to assume that the highlighted approaches are generalizable to a broader range of physical problems than considered to date. [ABSTRACT FROM AUTHOR]

We report a general, intramolecular cycloisomerization of unactivated olefins with pendant nucleophiles. The reaction proceeds under mild conditions and tolerates ethers, esters, protected amines, acetals, pyrazoles, carbamates, and arenes. It is amenable to N‐, O‐, as well as C‐nucleophiles, yielding a number of different heterocycles including, but not limited to, pyrrolidines, piperidines, oxazolidinones, and lactones. Use of both a benzothiazinoquinoxaline as organophotocatalyst and a Co‐salen catalyst obviates the need for stoichiometric oxidant or reductant. We showcase the utility of the protocol in late‐stage drug diversification and synthesis of several small natural products. [ABSTRACT FROM AUTHOR]

Skeleton editing has rapidly advanced as a synthetic methodology in recent years, significantly streamlining the synthesis process and gaining widespread acceptance in drug synthesis and development. This field encompasses diverse ring reactions, many of which exhibit immense potential in skeleton editing, facilitating the generation of novel ring skeletons. Notably, reactions that involve the cleavage of two distinct rings followed by the reformation of new rings through ring insertion play a pivotal role in the construction of novel ring skeletons. This article aims to compile and systematize this category of reactions, emphasizing the two primary reaction types and offering a thorough exploration of their associated complexities and challenges. Our endeavor is to furnish readers with comprehensive reaction strategies, igniting research interest and injecting fresh impetus into the advancement of this domain. [ABSTRACT FROM AUTHOR]

Four alkaline earth metal complexes of ketoprofen (Hket) and indomethacin (Hind) were synthesized and characterized: [Ca(ket)2(H2O)2]n (1), [Mg(ket)2(H2O)2] (2), [Ca(ind)2(EtOH)2]n (3), and [Mg(ind)2(EtOH)2] (4). All compounds were studied by elemental analysis (EA), flame atomic absorption spectrometry (FAAS), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). Crystal structures of 1 and 3 were determined by single crystal X‐ray diffraction technique T=100 K. The structure of 1 is dominated by a one‐dimensional coordination polymer, while 3 is formed by a two‐dimensional layer stabilized by the calcium zig‐zag chains and π⋅⋅⋅π stacking interactions. Crystal packing arrangements were characterized by fingerprint plots (FPs) that were derived from the Hirshfeld surfaces (HSs). The antioxidant and antimicrobial activities of complexes were evaluated against Gram‐positive and Gram‐negative bacteria as well as yeasts. [ABSTRACT FROM AUTHOR]

Synthesis of heterocyclic compounds is fundamental for all the research area in chemistry, from drug synthesis to material science. In this framework, catalysed synthetic methods are of great interest to effective reach such important building blocks. In this review, we will report on some selected examples from the last five years, of the major improvement in the field, focusing on the most important conventional catalytic systems, such as transition metals, organocatalysts, to more sustainable ones such as photocatalysts, iodine‐catalysed reaction, electrochemical reactions and green innovative methods. [ABSTRACT FROM AUTHOR]

Cariprazine—the only single antipsychotic drug in the market which can handle all symptoms of bipolar I disorder—involves trans-4-substituted cyclohexane-1-amine as a key structural element. In this work, production of trans-4-substituted cyclohexane-1-amines was investigated applying transaminases either in diastereotope selective amination starting from the corresponding ketone or in diastereomer selective deamination of their diasteromeric mixtures. Transaminases were identified enabling the conversion of the cis-diastereomer of four selected cis/trans-amines with different 4-substituents to the corresponding ketones. In the continuous-flow experiments aiming the cis diastereomer conversion to ketone, highly diastereopure trans-amine could be produced (de > 99%). The yield of pure trans-isomers exceeding their original amount in the starting mixture could be explained by dynamic isomerization through ketone intermediates. The single transaminase-catalyzed process—exploiting the cis-diastereomer selectivity of the deamination and thermodynamic control favoring the trans-amines due to reversibility of the steps—allows enhancement of the productivity of industrial cariprazine synthesis. Stereoselective production of trans-4-substituted cyclohexane-1-amines—including a key intermediate in the synthesis of antipsychotic drug cariprazine—remains challenging. Here, the authors develop a process catalyzed by a single transaminase to produce trans-4-substituted cyclohexane-1-amines from the corresponding cis/trans-diastereomeric mixtures via a cis-deamination approach in continuous-flow, to achieve a dynamic cis-to-trans isomerization. [ABSTRACT FROM AUTHOR]

The diselenide bond has attracted intense interest in redox-responsive drug delivery systems (DDSs) in tumor chemotherapy, due to its higher sensitivity than the most investigated bond, namely the disulfide bond. Here, a diselenide-bridged doxorubicin dimeric prodrug (D-DOXSeSe) was designed by coupling two doxorubicin molecules with a diselenodiacetic acid (DSeDAA) molecule via α-amidation, as a redox-triggered drug self-delivery system (DSDS) for tumor-specific chemotherapy. The drug release profiles indicated that the D-DOXSeSe could be cleaved to release the derivatives selenol (DOX-SeH) and seleninic acid (DOX-SeOOH) with the triggering of high GSH and H2O2, respectively, indicating the double-edged sword effect of the lower electronegativity of the selenide atom. The resultant solubility-controlled slow drug release performance makes it a promising candidate as a long-acting DSDS in future tumor chemotherapy. Moreover, the interaction between the conjugations in the design of self-immolation traceless linkers was also proposed for the first time as another key factor for a desired precise tumor-specific chemotherapy, besides the conjugations themselves. [ABSTRACT FROM AUTHOR]

Rapa functionalized carbon dots (Rapa-CDs) were target-oriented synthesized via free radical polymerization combination with hydrothermal carbonization technology. Rapa-CDs has a high synthetic yield of 63%. The solubility of Rapa-CDs with 9.41 g is improved 3.6×104 times higher than that of Rapa (2.6×10-4 g). Rapa-CDs show the ability to scavenge ROS, and suppress cell senescence via anti-oxidative stress and mTOR. [Display omitted] • Rapa-CDs with synthetic yield of 63% were target-oriented synthesized. • Rapa-CDs increase Rapa solubility by 3.6 × 104 times and show ROS scavenging ability. • Rapa-CDs suppress vascular cell senescence via anti-oxidative stress and mTOR. Suppression of vascular cell senescence is of great significance in preventing cardiovascular diseases such as hypertension and atherosclerosis. The oxidative stress damage caused by reactive oxygen species (ROS) can lead to cellular senescence. Rapamycin (Rapa) is well known to suppress cell senescence via mammalian target of rapamycin (mTOR) pathway. However, poor water solubility and lack of ROS scavenging ability limit the further development of Rapa. To improve the solubility of Rapa and endow with ROS scavenging ability, Rapa functionalized carbon dots (Rapa-CDs) are target-oriented synthesized via free radical polymerization combination with hydrothermal carbonization. Rapa-CDs improve the solubility of Rapa and show ROS scavenging abilities. The solubility of Rapa-CDs with 9.41 g is improved 3.6 × 104 times higher than that of Rapa (2.6 × 10-4 g). The half maximal inhibitory concentration (IC 50) of Rapa-CDs toward hydroxyl radical (•OH) and 2,2-Diphenyl-1-picrylhydrazyl free radical (DPPH•) are 0.18 and 0.17 mg/mL, respectively. Rapa-CDs show anti-oxidative stress effect in HEVECs (Human Umbilical Vein Endothelial Cells) via reducing ROS levels by 87 %. Rapa-CDs alleviate HUVECs senescence by suppressing mTOR overactivation, attenuate the expression of P53, P21 and P16. The study demonstrates the target-oriented synthesis of drugs functionalized CDs with anti-senescence via dual-pathway of anti-oxidative stress and mTOR. [ABSTRACT FROM AUTHOR]