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Indoles are common motifs in functional agricultural and pharmaceutical molecules. Heteroatom alkylation is the most frequently used chemical reaction in the pharmaceutical field. Developing protocols for the nucleophilic substitution of (indol-2-yl)methyl electrophiles is important for functionalizing indoles. There are few studies on the nucleophilic substitution at the 2′-position of the electrophiles without an electron-withdrawing group at the 1-position or substituents at the 2′- and 3-positions, where the existing approaches require high temperatures and long reaction times. In this study, we demonstrated rapid (7–12 s) and mild (25 °C) microflow nucleophilic substitution at the 2′-position of indole derivatives without an electron-withdrawing group at the 1-position and substituents at the 2′- or 3-positions. Comparable batch conditions resulted in a lower yield. [ABSTRACT FROM AUTHOR]

A series of 1-carbonyl-1H-indoles were prepared by 2-iodoanilines and calcium carbide in a one-pot reaction catalyzed by recyclable10% Pb/C, resulting in the corresponding substituted indoles in good yields. This protocol offers several advantages, including the utilization of sustainable, low-cost calcium carbide, an easy-to-handle acetylene source, and recyclable Pb/C catalysts. The synthesis of a series of 1-carbonyl-1H-indoles were prepared by 2-iodoanilines and calcium carbide in a one-pot reaction catalyzed by 10% Pb/C, resulting in the corresponding substituted indoles in good yields. This protocol offers several advantages, including the utilization of sustainable, low-cost feedstock, an easy-to-handle acetylene source, and recyclable Pb/C catalysts. [ABSTRACT FROM AUTHOR]

A highly enantioselective Pd/Bim-catalyzed dearomative Michael reaction applying polycyclic tropones as non-benzenoid aromatic Michael acceptors and arylboronic acids as aryl pronucleophiles has been developed. The bridged biaryls bearing central and axial chirality, including pentacyclic cyclohepta[b]indoles and 6,7-dihydrodibenzo- [a,c][7]annulen-5-ones, are generally generated in good to high yields and excellent enantioselectivities and can be readily transformed into useful derivatives. [ABSTRACT FROM AUTHOR]

An alternative approach to synthesize bis‐indolylmethanes (BIMs) via a unique p‐toluenesulfonic acid (PTSA) catalyzed dual Csp3−Csp2 bond‐breaking reaction has been reported here. In the reported protocol, 1,3,5‐trimethoxybenzene (TMB), an electron‐rich and sterically bulky arene, acts as a carbon‐based leaving group which can be recovered after the completion of the reaction. In this process, several BIMs of various indole derivatives can be synthesized from symmetrical triarylmethanes (TRAMs) containing bis‐TMB motifs. By modifying the reaction conditions, we could control the sequential bond cleavage of two Csp3−Csp2 bonds in starting TRAM. [ABSTRACT FROM AUTHOR]

We herein reported, a visible‐light‐induced K2S2O8 mediated cascade reaction of 3‐(2‐isocyanoethyl)indoles with α‐oxocarboxylic acids leading to diastereoselective synthesis of polycyclic spiroindolines bearing an N‐formyl unit derivative utilising the alkali metal salt K2S2O8 as a mediator under mild reaction conditions. This study offers an illustration of α‐oxocarboxylic acids and 3‐(2‐isocyanoethyl)indoles‐based reactions as it shows the involvement of glyoxolate ions without decarboxylation to access polycyclic spiroindolines bearing an N‐formyl unit analogue. The batch process can be extended to a continuous flow system using a glass tube loaded with K2S2O8 placed between the PFA capillary reactor, which can greatly advance the reaction efficiency and can even be promoted to gram‐scale synthesis. [ABSTRACT FROM AUTHOR]

Soybean meal and its processing products have been widely used in fish feeds. In aquaculture, there is a lack of effective targeted protection against food-borne enteritis caused by feeding soybean meal. Our preliminary research found that Indole-3-butyric acid (IBA) has the potential application value. The present research evaluated the influence of supplementing different levels of IBA to diets containing high soybean meal on juvenile pearl gentian grouper (Epinephelus fuscoguttatus♀ × E. lanceolatus♂). The feeding experiment lasted for eight weeks and the initial weight of the fish was 21.17 ± 0.02 g. The FM diet with fish meal as the main protein source was prepared. In addition, six diets were prepared in which soybean meal was used to replace some of the fish meal as a secondary protein source. IBA was added to these six diets at 0 g/kg, 0.8 g/kg, 1.6 g/kg, 2.4 g/kg, 3.2 g/kg, and 4.0 g/kg respectively. The growth performance of the 2.4 g/kg IBA-added group was significantly higher than that of the non-added group (P < 0.05); the group with IBA additions equal to or more than 2.4 g/kg had longer intestinal folds and more absorptive cells; the levels of ACP, LYS, C3, and C4 in the gut showed a significant quadratic trend of decreasing and then increasing with the increase of IBA and reached a minimum at 2.4 g/kg (P < 0.05); the gene expression of cytokines il1β, il17, tnfα, il4, il5, and tgfβ1 varied significantly among the groups with different IBA additions (P < 0.05). In addition, this study investigated the role of feeding 2.4 g/kg IBA on fish from the perspective of intestinal flora. In this study, we concluded that 2.4 g/kg IBA could be added to diets using soybean meal replacing 40% of fish meal, which had beneficial effects on growth performance, intestinal inflammation alleviation and intestinal flora homeostasis. This provides a theoretical basis for IBA to mitigate SBMIE in pearl gentian grouper and promote the further application of soybean meal in carnivorous fish. [ABSTRACT FROM AUTHOR]

Free radicals like reactive oxygen species (ROS) and reactive nitrogen species (RNS) cause cellular damage and contribute to thromboembolic diseases by promoting platelet activation and aggregation. Compounds that scavenge free radicals can reduce oxidative stress, decreasing platelet aggregation and thrombus formation. Despite their beneficial biological activities, indoles have clinical limitations due to poor bioavailability, solubility, rapid metabolism, and limited membrane permeability. We designed a new class of indole derivatives (10a–j) with a triazole linker and various amino acids to overcome these issues. These conjugates enhance solubility and bioavailability and possess antioxidant properties. Compounds 10f, 10g, and 10h showed improved permeability and significant anti-platelet aggregation effects, comparable to aspirin. These findings highlight the potential of these new indole derivatives as effective antithrombotic agents, warranting further exploration of their mechanisms and therapeutic applications. [ABSTRACT FROM AUTHOR]

Tryptophan (Trp) is an essential amino acid, whose metabolism is a key gatekeeper of intestinal homeostasis. Yet, its systemic effects, particularly on atherosclerosis, remain unknown. Here we show that high-fat diet (HFD) increases the activity of intestinal indoleamine 2, 3-dioxygenase 1 (IDO), which shifts Trp metabolism from the production of microbiota-derived indole metabolites towards kynurenine production. Under HFD, the specific deletion of IDO in intestinal epithelial cells leads to intestinal inflammation, impaired intestinal barrier, augmented lesional T lymphocytes and atherosclerosis. This is associated with an increase in serotonin production and a decrease in indole metabolites, thus hijacking Trp for the serotonin pathway. Inhibition of intestinal serotonin production or supplementation with indole derivatives alleviates plaque inflammation and atherosclerosis. In summary, we uncover a pivotal role of intestinal IDO in the fine-tuning of Trp metabolism with systemic effects on atherosclerosis, paving the way for new therapeutic strategies to relieve gut-associated inflammatory diseases. Previous studies suggested the importance of intestinal tryptophan metabolism for gut homeostasis and potential systemic effects but its role in atherosclerosis remains poorly studied. Here, the authors show that the specific deletion of intestinal IDO increases gut inflammation with remote effects on atherosclerosis that can be reversed through inhibiting intestinal serotonin production. [ABSTRACT FROM AUTHOR]

A silver-catalyzed chemoselective cascade nucleophilic addition of a P-centered anion to isocyanides and cyclization reaction was developed for the efficient and practical synthesis of a wide range of 2-phosphinoyl indole and indol-3-ol derivatives. Unlike the well-documented synthesis of phosphorus-functionalized heterocycles via a P-centered radical, an anionic reactivity profile of phosphine oxides is most likely involved in this domino transformation. [ABSTRACT FROM AUTHOR]

A new method for the synthesis of 2-(phenyl)indole via the cyclization of 2-(phenylethynyl)aniline in the presence of K2S was established, which was used to prepare 2-(phenyl)indole derivatives in high yields (66%-93%). Mechanistic studies have revealed that a trisulfur radical anion (S3•−) is generated from K2S, which acts as an initiator for the intramolecular addition of the alkyne and the amino group in o-alkynylaniline, ultimately leading to the formation of the indole derivative. This method provides a new way to prepare 2-(phenyl)indoles and a novel application of S3•− in organic synthesis. [ABSTRACT FROM AUTHOR]

Quinolines are biologically and pharmaceutically important N-heterocyclic aromatic compounds, which have broad applications in medicinal chemistry. Thus, their efficient synthesis has attracted extensive attention, and a broad range of synthetic strategies have been established. Of note, gold-catalyzed methodologies for the synthesis of quinolines have greatly advanced this field. Various gold-catalyzed intermolecular annulation reactions, such as annulations of aniline derivatives with carbonyl compounds or alkynes, annulations of anthranils with alkynes, and annulations based on A3-coupling reactions, as well as intramolecular cyclization reactions of azide-tethered alkynes, 1,2-diphenylethynes, and 2-ethynyl N-aryl indoles, have been developed. This review provides an overview of this exciting research area. Typical achievements in reaction methodologies and plausible reaction mechanisms are summarized. [ABSTRACT FROM AUTHOR]

This document provides information on the use of photoacid generators (PAGs) in catalysis, specifically in the Friedel-Crafts alkylation of indoles with aldehydes/ketones. The study focuses on diarylethenes and terarylenes as PAGs, which have advantages such as high quantum yields and autonomy. The researchers developed an environmentally friendly method for synthesizing diindolylmethane derivatives with potential antibacterial, antitumor, and antifungal activities. The document also provides detailed information on the synthesis and characterization of various compounds, including their physical properties and spectroscopic data. This information can be useful for researchers studying these compounds and their properties. [Extracted from the article]

Aqueous soluble and stable Cu(I) molecular catalysts featuring a catenane ligand composed of two dicationic, mutually repelling but mechanically interlocked macrocycles are reported. The ligand interlocking not only fine‐tunes the coordination sphere and kinetically stabilizes the Cu(I) against air oxidation and disproportionation, but also buries the hydrophobic portions of the ligands and prevents their dissociation which are necessary for their good water solubility and a sustained activity. These catenane Cu(I) complexes can catalyze the oxidative C−C coupling of indoles and tetrahydroisoquinolines in water, using H2O2 as a green oxidant with a good substrate scope. The successful use of catenane ligands in exploiting aqueous Cu(I) catalysis thus highlights the many unexplored potential of mechanical bond as a design element for exploring transition metal catalysis under challenging conditions. [ABSTRACT FROM AUTHOR]

An efficient one-pot pseudo three component cascade annulation reaction has been devised to generate the fluorescent β-carboline tethered imidazopyrido[3,4-b]indole derivatives. These scaffolds were afforded in high yields via one-pot cascade reaction of diversified β-carboline acetals with NH4Cl through the formation of three C–N bonds in a single operation. The current protocol is step-economical and offers high atom-economy, short reaction time and high structural diversity with excellent yields (57–90%). The synthesized compounds displayed promising photophysical properties and delivered luminescence quantum yield (ΦF) up to 55%. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The privileged C2‐symmetric rigid phenol‐type ligand is more attractive but challenging in asymmetric catalysis. Herein, we designed and synthesized a class of rigid‐featured chiral tridentate Phenol‐2NO ligands, that incorporate the advantages of both the phenol skeleton and pyrroloimidazolone‐based N‐oxide moiety, from readily available L‐prolinamides in operationally simple two steps and up to 44% overall yield. More importantly, using an achiral quinoline derivative as an additive, the newly developed Phenol‐2NO ligand could serve as the anioic ligand upon deprotonative activation to coordinate to Zn(II) to form a highly enantioselective catalyst for the asymmetric Michael‐type Friedel‐Crafts alkylation reaction of indoles with 2,3‐dioxopyrrolidines. Excellent yields (up to 90%) and high enantioselectivities (up to 99% ee) are obtained for a wide range of substrates under mild conditions. Experiments and DFT calculations revealed the reaction mechanism and the origins of the enantioselectivity. This also represented the first activation of phenol‐type ligand/metal complex by an achiral organic base as the additive in asymmetric catalysis. [ABSTRACT FROM AUTHOR]

This document provides detailed information about the synthesis and characterization of several compounds, specifically derivatives of spiro[benzofuran-2,3'-indolin]-2'-one. The compounds are described in terms of their physical properties, such as melting point and color, and their chemical structures are provided. The document includes data from nuclear magnetic resonance (NMR) and mass spectrometry (MS) analyses, as well as yield and diastereomeric ratio information for each synthesis. These compounds have potential applications in various fields. [Extracted from the article]

Indole, a versatile outstanding heterocyclic compound, engaged in numerous pharmacological properties due to their multiple biochemical processes. The remarkable indole moiety resembles with numerous protein structures. The fascinating molecular framework of indole makes its suitable for drug development. Indole derivatives mimic the peptides structure and bind reversibly to several enzymes, which contribute enormous opportunities to develop novel drugs with distinct mechanism of action Indole, a versatile outstanding heterocyclic compound, engaged in numerous pharmacological properties due to their multiple biochemical processes. The remarkable indole moiety resembles with numerous protein structures. The fascinating molecular framework of indole makes its suitable for drug development. Indole derivatives mimic the peptides structure and bind reversibly to several enzymes, which contribute enormous opportunities to develop novel drugs with distinct mechanism of actionIndole, a versatile outstanding heterocyclic compound, engaged in numerous pharmacological properties due to their multiple biochemical processes. The remarkable indole moiety resembles with numerous protein structures. The fascinating molecular framework of indole makes its suitable for drug development. Indole derivatives mimic the peptides structure and bind reversibly to several enzymes, which contribute enormous opportunities to develop novel drugs with distinct mechanism of actionIndole, a versatile outstanding heterocyclic compound, engaged in numerous pharmacological properties due to their multiple biochemical processes. The remarkable indole moiety resembles with numerous protein structures. The fascinating molecular framework of indole makes its suitable for drug development. Indole derivatives mimic the peptides structure and bind reversibly to several enzymes, which contribute enormous opportunities to develop novel drugs with distinct mechanism of action In the present work, synthesis and biological activity of new indole based derivatives as potent anti-inflammatory agent. The derivatives were schemed and substituted, they were checked for docking scores against the Cyclooxygenase II enzyme. From that 10 best docked compounds are selected and synthesized spectral data of the synthesized compounds was obtained from IR, 1HNMR, 13CNMR, and mass spectroscopy, among the tested compounds. From the docking results, compound A7 and A10 (9.2 Kcal/mol) shows the highest binding affinity against Cyclooxygenase II enzyme possesses anti-inflammatory activity. [ABSTRACT FROM AUTHOR]

In the present work, the indole derivative, namely, 3,3′,3″-methane-triyl-tris-1H-indol (tris-Ind), is synthesized and characterized as an organic electrode material in rechargeable lithium-ion batteries (RLIB). The structural characterization of the synthesized molecule is carried out using physicochemical techniques. The ball milling method is used for the lithiation process to form electroactive lithiated tris-Ind (Li-tris-Ind). The electrochemical activity of Li-tris-Ind is measured in aqueous and non-aqueous electrolytic media, and the results are compared. The aqueous cell system delivers an average cell potential of 0.76 V with a discharge capacity of 189 mAhg−1, whereas the non-aqueous cell system delivers an average potential of 1 V with 506 mAhg−1. The potentiostatic electrochemical impedance spectroscopic studies reveal the kinetics of finite diffusion. The organic electrode shows good cyclic stability and reproducibility in both systems, making it a significant practical material for RLIB applications. [ABSTRACT FROM AUTHOR]

We report an efficient site-selective synthetic method to C2 and C3 indanyl-substituted indole derivatives via 1,3-dithianyl induced Nazarov-type cyclization. In particular, C2-selective indanyl-substituted indoles were directly obtained by a BF3·Et2O-promoted sequence of intramolecular C3–C2 migration and Nazarov-type cyclization process. [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]

Here we report B(C6F5)3/CPA‐catalyzed enantioselective aza‐Diels–Alder reaction of 3,3‐difluoro‐2‐Aryl‐3H‐indoles with unactivated dienes to access chiral 10,10‐difluoro‐tetrahydropyrido[1,2‐a]indoles. This protocol allows the formation of pyrazole‐based C2‐quaternary indolin‐3‐ones with high enantioselectivities and regioselectivities. Moreover, gram‐scale synthesis of the 10,10‐difluoro‐tetrahydropyrido[1,2‐a]indole skeleton was successfully achieved without any reduction in both yield and enantioselectivity. [ABSTRACT FROM AUTHOR]

AbstractIn recent years, the role of microbial tryptophan (Trp) catabolism in host-microbiota crosstalk has become a major area of scientific interest. Microbiota-derived Trp catabolites positively contribute to intestinal and systemic homeostasis by acting as ligands of aryl hydrocarbon receptor and pregnane X receptor, and as signaling molecules in microbial communities. Accumulating evidence suggests that microbial Trp catabolism could be therapeutic targets in treating human diseases. A number of bacteria and metabolic pathways have been identified to be responsible for the conversion of Trp in the intestine. Interestingly, many Trp-degrading bacteria can benefit from the supplementation of specific dietary fibers and polyphenols, which in turn increase the microbial production of beneficial Trp catabolites. Thus, this review aims to highlight the emerging role of diets and food components, i.e., food matrix, fiber, and polyphenol, in modulating the microbial catabolism of Trp and discuss the opportunities for potential therapeutic interventions via specifically designed diets targeting the Trp-microbiome axis. [ABSTRACT FROM AUTHOR]

This article provides a comprehensive report on the rhodium(III)-catalyzed C–H activation in indole from 2017 to 2022. The direct functionalization of C–H bonds offers a more sustainable and economically sensible route in organic synthesis, reducing the production of hazardous waste. Rhodium has been widely used as a catalyst for C–H functionalization due to its excellent functional group compatibility, versatility, reactivity, and selectivity. The article focuses on the utilization of Rh(III) catalyst for C–H activation of the indole moiety, which is a structurally important building block in natural products and pharmaceutical treatments. Various methods for directed C–H functionalization of indoles, such as C2 activation, alkylation, hydroarylation, and dual C–H activation reactions, are discussed. The text also discusses various methods for the synthesis of carbazole derivatives, benzo[e]indoles, and selective functionalization of indoles through C–H activation. While progress has been made in this area, there are still challenges to overcome, such as the need for harsh reaction conditions and stoichiometric metal oxidants. Continued research in this field is expected to improve reaction conditions and increase overall efficiency. [Extracted from the article]

This document provides a summary of various methods for the synthesis of tetrasubstituted axially chiral alkenes. The methods discussed include urea group-directed organocatalytic dihalogenation, Rh(III)-catalyzed C-H activation and directing group migration, cationic rhodium(I)/H8-BINAP-catalyzed chelation-controlled cycloaddition, Cu/Pd dual catalysis for arylboration, nickel-catalyzed cross-electrophile trans-aryl-benzylation, palladium-catalyzed C-H functionalization, Pd(II)-catalyzed thioether-directed alkenyl C-H olefination, Suzuki-Miyaura cross-coupling, asymmetric N-alkylation, chiral phosphoric acid catalyzed kinetic resolution, and asymmetric allylic substitution-isomerization. The methods demonstrate broad substrate scope and high enantioselectivities, but further research is needed to explore stereodivergent synthesis and applications in pharmaceutical chemistry. [Extracted from the article]

Heyns/Amadori rearrangement allows the synthesis of α-aminocarbonyl compounds from α-hydroxycarbonyls and amines via the generation of an aminoenol intermediate. In the present work, the in situ generated aminoenol intermediate has been efficiently trapped with ketones/aldehydes for the construction of N-heterocycles. This method offers access to various substituted indole derivatives with a high level of regioselectivity through the intramolecular trapping of the aminoenol intermediate derived from o-acyl/formylanilines and α-hydroxydimethylacetals/ketals followed by rearrangement/aromatization in the presence of acid. Important features include the use of α-hydroxydimethylacetal/ketal as an α-hydroxycarbonyl equivalent, excellent regiocontrol, good functional group tolerance, selective synthesis of acylindoles, gram-scale synthesis, and synthesis of higher analogues of indoles and anti-tumor agent. [ABSTRACT FROM AUTHOR]

A series of cyclometallated gold(III) complexes 21–27 of general formula [Au(dppta)(azdtc)Cl] (dppta = N,N-diisopropyl-P,P-diphenylphosphinothioic amide-κ2C,S; azdtc = azol(in)ium-2-dithiocarboxylate-κ1S) were prepared and characterized by spectroscopic and diffractometric techniques. Treatment of [Au(dppta)(azdtc)Cl] complexes with methanol led to their quantitative transformation into a novel family of (C^S, S^S)-cyclometallated gold(III) complexes of general formula [Au(dppta)(azmtd)] (azmdt = azol(in)ium-2-(methoxy)methanedithiol-κ2S,S) 28–34. All the [Au(dppta)(azdtc)Cl] complexes 21–27 catalyzed the alkylation of indoles, whereas [Au(dppta)(azmtd)] complexes 28–34 were inactive. Among the synthesized derivatives, complex 22 displayed the highest catalytic activity, leading to a series of functionalized indoles in excellent yields. [ABSTRACT FROM AUTHOR]

Fungi possess well-developed secondary metabolism pathways that are worthy of in-depth exploration. The One Strain Many Compounds (OSMAC) strategy is a useful method for exploring chemically diverse secondary metabolites. In this study, continued chemical investigations of the marine red algae-derived endophytic fungus Penicillium oxalicum 2021CDF-3 cultured in PDB media yielded six structurally diverse indole derivatives, including two new prenylated indole alkaloids asperinamide B (1) and peniochroloid B (5), as well as four related derivatives (compounds 2-4 and 6). The chemical structures of these compounds, including the absolute configurations of 1 and 5, were determined by extensive analyses of HRESIMS, 1D and 2D NMR spectroscopic data, and TDDFT-ECD calculations. Compound 1 was found to possess an unusual 3-pyrrolidone dimethylbenzopyran fused to the bicyclo[2.2.2]diazaoctane moiety, which was rare in previously reported prenylated indole alkaloids. In vitro cytotoxic experiments against four human tumor cell lines (HeLa, HepG2, FADU, and A549) indicated that 1 strongly inhibited the FADU cell line, with an IC50 value of 0.43 ± 0.03 µM. This study suggested that the new prenylated indole alkaloid 1 is a potential lead compound for anti-FADU drugs. [ABSTRACT FROM AUTHOR]

Lentiviral vectors derived from human immunodeficiency virus type I are widely used to deliver functional gene copies to mammalian cells for research and gene therapies. Post-transcriptional splicing of lentiviral vector transgene in transduced host and transfected producer cells presents barriers to widespread application of lentiviral vector-based therapies. The present study examined effects of indole derivative compound IDC16 on splicing of lentiviral vector transcripts in producer cells and corresponding yield of infectious lentiviral vectors. Indole IDC16 was shown previously to modify alternative splicing in human immunodeficiency virus type I. Human embryonic kidney 293T cells were transiently transfected by 3rd generation backbone and packaging plasmids using polyethyleneimine. Reverse transcription-quantitative polymerase chain reaction of the fraction of unspliced genomes in human embryonic kidney 293T cells increased up to 31% upon the indole's treatment at 2.5 uM. Corresponding yield of infectious lentiviral vectors decreased up to 4.5-fold in a cell transduction assay. Adjusting timing and duration of IDC16 treatment indicated that the indole's disruption of early stages of transfection and cell cycle had a greater effect on exponential time course of lentiviral vector production than its reduction of post-transcriptional splicing. Decrease in transfected human embryonic kidney 293T proliferation by IDC16 became significant at 10 uM. These findings indicated contributions by early-stage transfection, cell proliferation, and post-transcriptional splicing in transient transfection of human embryonic kidney 293T cells for lentiviral vector production. [ABSTRACT FROM AUTHOR]

Utilizing iron chloride as a Lewis acid catalyst, we developed a straightforward and mild oxidative cross-coupling reaction between quinoxalinones and indoles, yielding a series of versatile 3-(indol-3-yl)quinoxalin-2-one derivatives. This approach allows for the incorporation of a wide array of functional groups into the final products, demonstrating its synthetic versatility. Notably, the method was successfully scaled up to gram-scale reactions while maintaining high yields. Our mechanistic investigation indicates that iron chloride serves as a catalyst to facilitate the formation of key intermediates which subsequently undergo oxidation to afford the desired products. The merits of this protocol include its cost effectiveness, operational simplicity, and the ease of product isolation via filtration. [ABSTRACT FROM AUTHOR]

The total synthesis of alternatamines B and D is outlined. Alternatamine B demonstrates moderate antibacterial activity across a broad spectrum of bacteria. Both alternatamines B and D feature an intriguing 5,6‐dibromoindole skeleton, derived from a four‐step sequence starting with 3,4‐dibromoaniline and achieving a total yield of 48 %. The key steps involve: (a) functional group modifications, including iodination, of 3,4‐dibromoaniline with two bromine substituents to obtain the Sonogashira precursor; (b) indole synthesis through Sonogashira coupling and 5‐endo‐dig cyclization; (c) carbon chain extension and introduction of the nitrogen atom at the C3 of the indole. Subsequently, the tryptamine analogue was coupled with an L‐leucine derivative through amide bond formation after deprotection, yielding alternatamide D. The first total synthesis of alternatamine B was also achieved by selectively introducing a bromine substituent at the C2 of the indole, employing optimal bromination conditions. [ABSTRACT FROM AUTHOR]

An efficient method has been developed to facilitate the addition‐ring opening cascade reaction of vinylogous oxindole, resulting in the synthesis of a variety of aza‐bicyclic maleimide derivatives with high yields and exceptional diastereoselectivities. Furthermore, the product could be effectively and easily transformed into the difluoromethylenecyclohexane skeleton through a dehydrofluorination process. This methodology demonstrates significant potential for the synthesis of aza‐bicyclic maleimide skeleton, which possesses biological or pharmaceutical activity. [ABSTRACT FROM AUTHOR]

We present an Ugi multicomponent approach to explore the chemical space around Aspidosperma‐type monoterpene indole alkaloids. By variation of the isocyanide and carboxylic acid inputs we demonstrate the rapid generation of molecular diversity and the possibility to introduce handles for further modification. The key Ugi three‐component reaction showed full diastereoselectivity towards the cis‐fused ring system, which can be rationalized by DFT calculations that moreover indicate that the reaction proceeds via a Passerini‐type hydrogen bonding mechanism. Several post‐Ugi modifications were also performed, including Pictet‐Spengler cyclization to highly complex nonacyclic natural product hybrid scaffolds. [ABSTRACT FROM AUTHOR]

A protocol for trans-hydroboration of indole derivatives using heterogeneous photocatalysis with NHC-borane has been developed, addressing a persistent challenge in organic synthesis. The protocol, leveraging high crystalline vacancy-engineered polymeric carbon nitride as a catalyst, enables diastereoselective synthesis, expanding substrate scope and complementing existing methods. The approach emphasizes eco-friendliness, cost-effectiveness, and scalability, making it suitable for industrial applications, particularly in renewable energy contexts. The catalyst's superior performance, attributed to its rich carbon-vacancies and well-ordered structure, surpasses more expensive homogeneous alternatives, enhancing viability for large-scale use. This innovation holds promise for synthesizing bioactive compounds and materials relevant to medicinal chemistry and beyond. Dearomative hydroboration of predominantly existing indole derivatives provides a straightforward strategy to synthesize boryl indolines, but developing eco-friendly methods for remains challenging. Here, the authors develop a method for heterogeneous photocatalytic trans-hydroboration of indole derivatives with NHC-borane. [ABSTRACT FROM AUTHOR]

When a mixture containing 1‐halo‐1‐alkyne, a dinucleophilic agent, and a base (Cs2CO3 or K3PO4) was heated in DMF, regio‐ and stereo‐selective nucleophilic addition of the dinucleophilic agent to the acetylenes occurred. This reaction yielded (Z,Z)‐bis(haloalkene), which subsequently underwent Pd‐catalyzed cyclization through C−H bond activation, resulting in the formation of two‐oxygen‐ or ‐nitrogen‐containing hetero‐π‐conjugated compounds. N‐(5‐Hydroxynaphthalen‐1‐yl)methanesulfonamide was treated with 2‐phenyl‐1‐chloroethyne followed by 1‐chloro‐1‐hexadecyne. After these reactions, Pd‐catalyzed double C−H cyclization was employed to produce 1H‐2‐phenyl‐7‐tetradecylbenzofuro[7,6‐g]indole. Notably, this compound transformed into a fan‐shaped structure at 86 °C and transitioned into a smectic A phase characterized by a layered structure. [ABSTRACT FROM AUTHOR]

α‐Indol‐3‐yl α,β‐unsaturated carbonyl compounds are synthesized from 3‐propargyl indoles, obtained by direct propargylation of indoles, via a gold‐catalyzed tandem oxidation‐1,2‐indole migration reaction in the presence of pyridine N‐oxides. Fine‐tuning of the catalyst and oxidant enables the reaction of 3‐propargyl indoles bearing different substituents. The order of oxidation and indole migration is determined by the terminal or internal nature of the alkyne moiety. In addition, the process can be coupled with additional reactions, allowing an increase in molecular complexity or the design of more elaborated tandem reactions. In this sense, indole derivatives bearing an alkenyl substituent at the alkyne position evolve through a gold‐catalyzed tandem oxidation‐1,2‐indole migration‐Nazarov cyclization producing α‐indolyl cyclopentenones. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: A mild and practical method for synthesizing fluorinated quinoline derivatives, which have a wide range of applications in pharmaceuticals, materials, and organic synthesis, was described through C—F bond insertion into indoles using CHBr2F. The simple conditions, readily availability of CHBr2F, as well as the versatility of the transformations make this strategy very powerful in synthesizing 3‐fluoroquinoline and 3‐fluoroquinolone. The mechanistic studies reveal that bromofluorocarbene generated in‐situ under basic condition was the key intermediate. [ABSTRACT FROM AUTHOR]

Alkaloids are natural compounds useful as scaffolds for discovering new bioactive molecules. This study utilized alkaloid gramine to synthesize two groups of C3-substituted indole derivatives, which were either functionalized at N1 or not. The compounds were characterized by spectroscopic methods. The protective effects of the new compounds against in vitro oxidative hemolysis induced by standard oxidant 2,2′-azobis(2-amidinopropane dihydro chloride (AAPH) on human erythrocytes as a cell model were investigated. Additionally, the compounds were screened for antimicrobial activity. The results indicated that most of the indole derivatives devoid of the N1 substitution exhibited strong cytoprotective properties. The docking studies supported the affinities of selected indole-based ligands as potential antioxidants. Furthermore, the derivatives obtained exhibited potent fungicidal properties. The structures of the eight derivatives possessing indole moiety bridged to the imidazole-, benzimidazole-, thiazole-, benzothiazole-, and 5-methylbenzothiazoline-2-thiones were determined by X-ray diffraction. The C=S bond lengths in the thioamide fragment pointed to the involvement of zwitterionic structures of varying contribution. The predominance of zwitterionic mesomers may explain the lack of cytoprotective properties, while steric effects, which limit multiple the hydrogen-bond acceptor properties of a thione sulfur, seem to be responsible for the high hemolytic activity. [ABSTRACT FROM AUTHOR]

A novel [3+3] annulation reaction of 2‐alkenylindoles with hydrazonyl chlorides in the presence of base for the formation of pyridazino[4,5‐b]indoles was developed. This approach provided a convenient and efficient way to synthesize a series of functionalized pyridazino[4,5‐b]indoles derivatives. The method exhibited a broad substrate scope and provided the corresponding pyridazino[4,5‐b]indoles products with excellent yields. [ABSTRACT FROM AUTHOR]

Pyrrolo[1,2-a]indoles are structurally important scaffolds in many natural products and bioactive compounds. Herein, we report a novel synthetic method for pyrrolo[1,2-a]indole derivatives through visible-light-induced cascade dearomatizative cyclization of indoles with external nucleophiles. Moderate yields, good diastereoselectivities, and excellent regioselectivities were generally observed with the resultant indole-fused polycyclic compounds. [ABSTRACT FROM AUTHOR]

In the present work, novel series of Schiff base 2-7 were synthesized via treatment of p-tosyloxy benzaldehyde with some indole and quinoxaline derivatives in ethanol under reflux. All product structures were verified using elemental analysis and spectroscopic investigations, including 13C NMR, 1H NMR, and IR. Our research was conducted on the insecticidal activity, and biological effects of the recently synthesized Schiff bases on S. frugiperda. The results showed that compound 5 was the most active insecticide, nearly surpassing methomyl as a reference, with LC50 values of 46.35 mg/L for second-instar larvae and 97.37 mg/L for fourth-instar larvae. This research opened up new avenues for the search for a novel class of insecticide. [ABSTRACT FROM AUTHOR]

A three component reaction employing readily available starting materials: 2‐(1‐pyrrolyl)benzylamine, arylglyoxal monohydrates and electron‐deficient alkenes in the synthesis of dipyrrolobenzo[1,2‐a : 2′,1′‐c][1,4]diazepines ‐ previously undescribed system and indolo[2,1‐c]pyrrolo[1,2‐a][1,4]benzodiazepine derivatives have been shown. Domino reactions of pyrrolo[1,2‐a][1,4]benzodiazepines with electron‐deficient alkenes has been proposed as another approach. The applicability of the three‐component reaction for the synthesis of indolizino[8,7‐b]indole derivatives from tryptamine has been studied. The in vitro biological activity of title compounds has been tested. [ABSTRACT FROM AUTHOR]

We report an innovative synthetic strategy for the generation of polysubstituted indoles from indolines, aryldiazonium salts, and azoles. The methodology encompasses an electrophilic substitution reaction affording C5-indoline intermediates which undergo an iodine-mediated oxidative transformation coupled with C–H functionalization to yield the indole derivatives. [ABSTRACT FROM AUTHOR]

We report herein an enantioselective [3+3] annulation of indoline‐2‐thiones with yne–enones by chiral dinuclear zinc catalysts via a Brønsted base and Lewis acid cooperative activation model. This transformation proceeded through sequential conjugate addition, allenyl ketone formation and intramolecular sulfa‐Michael 6‐endo‐trig cyclization. A range of enantioenriched tetrahydrothiopyrano[2,3‐b]indole derivatives bearing an exocyclic double bond were obtained in moderate yields with excellent stereoselectivities (up to 20 : 1 dr, 20:1 Z/E ratio and 95% ee). Late‐stage functionalization, large‐scale experiment and further derivatizations were also explored. [ABSTRACT FROM AUTHOR]

A transition‐metal‐free dearomative aza‐spirocyclization reaction of 2,3‐disubstituted indoles is established by using molecular iodine under basic conditions. The required substrates were prepared via sequential Fisher indole synthesis and sulfonylation. This dearomatization reaction is amenable to gram‐scale synthesis, and provides access to various spiroindolenine derivatives from indole sulfonamide precursors. [ABSTRACT FROM AUTHOR]

Herein, we describe a base‐promoted regioselective and chemoselective cascade cyclization, ynamide N−Csp bond cleavage, selective intramolecular 1,3‐migration, and simultaneous N‐desulfonylation strategy for the synthesis of 2‐phenyl‐3‐(phenylethynyl)‐1H‐indole derivatives. We observed multiple bond breaking (−N−Ts, and Csp2−Ts, Csp2−I/Csp2−SePh) from (E)‐3‐(1‐iodo‐2‐phenyl‐2‐tosylvinyl)‐2‐phenyl‐1‐tosyl‐indole/(E)‐2‐phenyl‐3‐(2‐phenyl‐1‐(phenylselanyl)‐2‐tosylvinyl)‐1‐tosyl‐indole derivatives to prepare 2‐phenyl‐3‐(phenylethynyl)‐1H‐indole in 15–60 min using our standard reaction conditions. A gram‐scale experiment as well as postsynthetic transformations of the synthesized 2‐phenyl‐3‐(phenylethynyl)‐1H‐indole were performed to exhibit the advantages of this synthetic methodology. [ABSTRACT FROM AUTHOR]

The area of combining an enzyme and transition metals to catalyse the sequence of reactions in one-pot which improve total conversion and operational stability has seen tremendous growth in recent years. Herein, we describe the synthesis and substrate controlled modification of β-aminocarbonyl using α-amylase enzyme and Pd-based catalyst in the one-pot. Moreover, the chemo-enzymatic approach provides substituted indole derivatives unprecedentedly when isocyanide was used in the reaction. In the second phase, isocyanide was replaced by phenyl boronic acid which in turn provides the substituted amino biaryls in good yield. Next, the feasibility of one-pot chemo-enzymatic approach was proved by employing substituted 2-bromo aniline along with different isocyanide/phenyl boronic acid and obtained the corresponding products in 56–84% isolated yield. [ABSTRACT FROM AUTHOR]

A Pd‐catalyzed formal [3+2] oxidative annulation of N‐aryl‐2‐aminopyridines and alkynes through pyridyl group directed C−H activation has been developed. This methodology provides a mild and atom‐economic approach for the efficient synthesis of highly substituted indoles in moderate to good yields, which features with mild reaction conditions, good functional group compatibility, operational simplicity and easy scale‐up. [ABSTRACT FROM AUTHOR]

Abstract Background The host–microbiota interaction plays a crucial role in maintaining homeostasis and disease susceptibility, and microbial tryptophan metabolites are potent modulators of host physiology. However, whether and how these metabolites mediate host–microbiota interactions, particularly in terms of inter-microbial communication, remains unclear. Results Here, we have demonstrated that indole-3-lactic acid (ILA) is a key molecule produced by Lactobacillus in protecting against intestinal inflammation and correcting microbial dysbiosis. Specifically, Lactobacillus metabolizes tryptophan into ILA, thereby augmenting the expression of key bacterial enzymes implicated in tryptophan metabolism, leading to the synthesis of other indole derivatives including indole-3-propionic acid (IPA) and indole-3-acetic acid (IAA). Notably, ILA, IPA, and IAA possess the ability to mitigate intestinal inflammation and modulate the gut microbiota in both DSS-induced and IL-10−/− spontaneous colitis models. ILA increases the abundance of tryptophan-metabolizing bacteria (e.g., Clostridium), as well as the mRNA expression of acyl-CoA dehydrogenase and indolelactate dehydrogenase in vivo and in vitro, resulting in an augmented production of IPA and IAA. Furthermore, a mutant strain of Lactobacillus fails to protect against inflammation and producing other derivatives. ILA-mediated microbial cross-feeding was microbiota-dependent and specifically enhanced indole derivatives production under conditions of dysbiosis induced by Citrobacter rodentium or DSS, but not of microbiota disruption with antibiotics. Conclusion Taken together, we highlight mechanisms by which microbiome-host crosstalk cooperatively control intestinal homoeostasis through microbiota-derived indoles mediating the inter-microbial communication. These findings may contribute to the development of microbiota-derived metabolites or targeted “postbiotic” as potential interventions for the treatment or prevention of dysbiosis-driven diseases. Video Abstract

A visible-light-promoted research protocol for constructing dihydropyrido[1,2-a]indolone skeletons is herein described proceeding through a cascade cyclization mediated by trifluoromethyl radicals. This method allows the efficient synthesis of various indole derivatives without the need of photocatalysts or transition-metal catalysts. Mechanism experiments indicate that the process involves a radical chain process initiated by the homolysis of Umemoto's reagent. This straightforward method enables a rapid access to heterocycles containing a trifluoromethyl group.