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An organophotocatalytic method has been described towards the synthesis of indolines and oxindoles starting from unusual α-chloro amide and N-(2-chlorophenyl)-N-alkyl methacrylamide substrates. This marks a notable improvement since the earlier syntheses utilized iridium and gold catalysts, and involved C–I or C–Br bond cleavage as the initial step. Our photocatalyst is a pincer ligand that can be easily deprotonated to make a very strong reducing agent. The reductive cleavage of the carbon–chloride bond, and subsequent 5-exo-trig ring cyclization, followed by hydrogen atom abstraction, prepare the desired heterocycles under very mild reaction conditions. An atom economic use of KOtBu has been shown to demonstrate the unusual trifunctional role of the latter. [ABSTRACT FROM AUTHOR]

A highly efficient catalytic nucleophilic addition of 3‐substituted oxindoles to 3‐diazo oxindoles has been achieved. This method relies on an organic base catalysis system, which can simultaneously activate 3‐substituted oxindoles as a nucleophile and the diazo compounds as a strong N‐terminal electrophile. Importantly, this approach could yield a broad array of functionalized isatin‐hydrazones featuring an adjacent tetrasubstituted carbon centre of the N(sp3) atom. [ABSTRACT FROM AUTHOR]

Fluorine being a magic element and Indole being a magic molecule, their cumulative effect has tremendously increased the potential of resulting moiety for drug development. Keeping this in mind, we are describing a comprehensive account on the recent strategies for the synthesis of trifluoromethylated indoles, indoline and oxindoles. In this review we have explored two types of strategies for trifluoromethylation reactions, one involves direct installation of CF3 group at indole moiety via C−H activation and substitution where as other is by the cyclization reaction of the starting compound containing CF3 group. The reactions were explored for the substrate scope and mechanism using controlled experiments. [ABSTRACT FROM AUTHOR]

The construction of chiral motifs containing nonadjacent stereocenters in an enantio‐ and diastereoselective manner has long been a challenging task in synthetic chemistry, especially with respect to their stereodivergent synthesis. Herein, we describe a protocol that enables the enantio‐ and diastereoselective construction of 1,5/1,7‐nonadjacent tetrasubstituted stereocenters through a Pd/Cu‐cocatalyzed Heck cascade reaction. Notably, a C=C bond relay strategy involving the shift of the π‐allyl palladium intermediate was successfully applied in the asymmetric construction of 1,7‐nonadjacent stereocenters. The current method allows for the efficient preparation of chiral molecules bearing two privileged scaffolds, oxindoles and non‐natural α‐amino acids, with good functional group tolerance. The full complement of the four stereoisomers of products bearing 1,5/1,7‐nonadjacent stereocenters could be readily accessed by a simple combination of two chiral metal catalysts with different enantiomers. [ABSTRACT FROM AUTHOR]

A convenient approach for synthesizing indole‐N‐carboxamide derivatives through palladium‐catalyzed isocyanide insertion into the N−H bond of 3‐(phenylhydrazono)oxindoles has been developed. The inclusion of the 3‐phenylhydrazone group proved essential in remotely activating the N−H bond of the oxindole. Also, it has been established that the reaction outcome is highly dependent on the electronic effects of the substituents. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: A novel electrochemical multicomponent cascade reaction of indole‐tethered alkenes with CF3SO2Na and n‐Bu4NI has been developed, which enables the rapid assembly of spiropyrrolidinyl‐oxindoles in good yields. The experimental results and DFT calculations suggest that this reaction proceeds through the oxidation of CF3SO2Na, radical coupling with alkene, spirocyclization, oxidation of sulfinate, iodide substitution, and water coupling. This strategy features mild reaction conditions, easy‐to‐handle reactants, and good chemical yields. This finding not only enriches the research contents of indole‐tethered alkenes but also provides a green strategy for the construction of spiropyrrolidinyl‐oxindoles compared with the existing methodologies. [ABSTRACT FROM AUTHOR]

Malamides (diamide derivatives of malic acid) are prevalent in nature and of significant biological interest, yet only limited synthetic methods to access functionalised enantiopure derivatives have been established to date. Herein, an effective synthetic method to generate this molecular class is developed through in situ formation of spirocyclic β-lactone-oxindoles (employing a known enantioselective isothiourea-catalysed formal [2+2] cycloaddition of C(1)-ammonium enolates and isatin derivatives) followed by a subsequent dual ring-opening protocol (of the β-lactone and oxindole) with amine nucleophiles. The application of this protocol is demonstrated across twelve examples to give densely functionalised malamide derivatives with high enantio- and diastereo-selectivity (up to >95:5 dr and >99:1 er). [ABSTRACT FROM AUTHOR]

Axially chiral cycloalkylidenes are interesting but less developed axially chiral molecules. Here, a bispidine‐based chiral amine catalytic system was developed to promote efficiently the asymmetric Knoevenagel condensation of N‐protected oxindoles and benzofuranones with 4‐substituted cyclohexanones. A variety of alkylidenecycloalkanes with stable axial chirality were obtained in good yields and fairly good er (enantiomeric ratio). Based on the absolute configuration determination of product and DFT calculations, a possible mechanism of stereoselective induction was proposed. [ABSTRACT FROM AUTHOR]

A protocol has been developed for the synthesis of α‐aryl‐oxindoles from isatin and Grignard reagents in the presence of diphenyl phosphite for the first time. This reaction was conveniently carried out under mild conditions in a one‐pot fashion with moderate to excellent yields. [ABSTRACT FROM AUTHOR]

An iron‐catalyzed protocol for the synthesis of 3‐amino‐3‐aminomethyl‐2‐oxindole heterocyclic structures is disclosed employing isatins and non‐nucleophilic N‐methoxybenzamides. This reaction class is associated with broad scope and tolerates numerous functionalities, such as fluoro, chloro, bromo, iodo, trifluoromethyl, nitrile, ester, ether, and alkenyl, including heteroaryl – thiophene, benzothiophene, carbazolyl, indolyl, eugenol, and polycyclic cholesterol moieties. Detailed mechanistic investigations reveal that the reaction proceeds via iron‐catalyzed N−O bond cleavage in N‐methoxybenzamides, generating formaldehyde and benzamide, and through the intermediacy of isatin‐ketimines and N‐(hydroxymethyl)benzamides. Overall, this amidation reaction involves one C−C and two C−N bond‐forming tandem processes, providing a range of β‐amino‐aminomethyl‐oxindoles (45 examples) in up to 88% yields. [ABSTRACT FROM AUTHOR]

A photochemical synthesis of biologically relevant benzyl oxindoles is presented via electron‐donor acceptor (EDA) complex strategy. This exogenous photocatalyst‐free method describes the formation of a new electron donor‐acceptor complex based on potassium carbonate and thianthrenium salts for C(sp2)−C(sp3) bond formation. This transition‐metal free reaction allows a rapid increase in oxindoles molecular complexity chemical space, tolerating different functional groups as well as sophisticated biomolecules. The scalability and sustainability of this method is highlighted by an important waste recovery protocol. Mechanistic investigations support the formation of an EDA complex that induces a radical chain, and the applicability of this method is showcased by straightforward derivatization reactions. [ABSTRACT FROM AUTHOR]

A visible-light-induced difunctionalization of activated alkenes for building alkylsulfonylated oxindoles and amides through a radical Smiles rearrangement strategy was reported. A tandem SO2 insertion/1,4-aryl migration/desulfonylation/cyclization sequence was involved in this transformation. Readily available Hantzsch esters served as alkylation reagents. Two different products were constructed depending on the substituent group of the nitrogen atom. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Herein, we report an efficient and practical protocol for the photoinduced dehalocyclization of ortho‐halophenylacrylamides with formate by the engagement of a CO2 radical anion to access substituted oxindoles. This method proceeds smoothly under mild conditions and exhibits a wide range of substrate as well as remarkable functional group compatibility. [ABSTRACT FROM AUTHOR]

The transition‐metal‐free synthesis of organic compounds especially heterocycles is in resonance with one of the twelve principles proposed by Prof. Paul Anastas in his renowned work towards the sustainable development of green chemistry. Traditional‐metal‐catalyzed reactions often involve expensive or toxic metal catalysts, and there is a growing interest in developing more sustainable and environmentally friendly methods. The arylation of heterocycles is an important area of research in organic chemistry, particularly in the synthesis of biologically active compounds and pharmaceuticals. Arylation of heterocycles at different positions enhances the potency and stability of biologically and pharmaceutically important scaffolds. In this review, an overview of the synthetic protocols developed for the arylation of a variety of heterocyclic compounds including, pyrroles, pyridines, thiophene, indole, oxindoles, purines, xanthene, etc. has been described. [ABSTRACT FROM AUTHOR]

Alkenyl oxindoles have been characterized as autophagosome-tethering compounds (ATTECs), which can target mutant huntingtin protein (mHTT) for lysosomal degradation. In order to expand the application of alkenyl oxindoles for targeted protein degradation, we designed and synthesized a series of heterobifunctional compounds by conjugating different alkenyl oxindoles with bromodomain-containing protein 4 (BRD4) inhibitor JQ1. Through structure-activity relationship study, we successfully developed JQ1-alkenyl oxindole conjugates that potently degrade BRD4. Unexpectedly, we found that these molecules degrade BRD4 through the ubiquitin-proteasome system, rather than the autophagy-lysosomal pathway. Using pooled CRISPR interference (CRISPRi) screening, we revealed that JQ1-alkenyl oxindole conjugates recruit the E3 ubiquitin ligase complex CRL4DCAF11 for substrate degradation. Furthermore, we validated the most potent heterobifunctional molecule HL435 as a promising drug-like lead compound to exert antitumor activity both in vitro and in a mouse xenograft tumor model. Our research provides new employable proteolysis targeting chimera (PROTAC) moieties for targeted protein degradation, providing new possibilities for drug discovery. Targeted protein degradation strategies are promising avenues for drug development, but it is important to broaden the toolbox of E3 ligases that can be engaged. This study shows that alkenyl oxindole compounds act as novel E3 ligase ligands and recruit the CRL4-DCAF11 E3 ubiquitin ligase complex for substrate degradation. [ABSTRACT FROM AUTHOR]

This article discusses a new method for synthesizing spirocyclopentene oxindoles, which are found in natural products and biologically active molecules. The authors describe the synthesis process using lithium bis(trimethylsilyl)amide (LiHMDS) and ring closing metathesis. The yields of the desired compounds ranged from 55% to 88%, with some side products observed in certain cases. The authors provide detailed physical and spectroscopic data for each compound synthesized. The article acknowledges the institutions that provided resources and support for the research. [Extracted from the article]

We reported a visible‐light‐induced iron‐catalyzed α‐alkylation of oxindoles with alcohols to offer a variety of α‐alkyled oxindoles at room temperature. This reaction featured broad substrate scope with good functional tolerance under simple conditions. Through a series of controlled experiments, we tried to elucidated the important role of light in this borrowing hydrogen (BH) reaction. [ABSTRACT FROM AUTHOR]

Asymmetric synthesis of 3-sulfonylated 3-substituted oxindoles through the addition of sodium sulfinate salts to 3-bromo-3-substituted oxindoles has been achieved using chiral nickel complexes of N,N′-dioxides. This method facilitates the creation of diverse chiral sulfonyl oxindoles, several of which display promising anticancer properties. Notably, the catalyst demonstrates remarkable tolerance to water, crucial for maintaining enantioselectivity. Furthermore, the utilization of topographic steric maps of the catalysts offers valuable insights into the mechanism underlying enantioselection reversal. [ABSTRACT FROM AUTHOR]

A tert‐butyl nitrite (TBN) promoted visible‐light‐induced one‐pot C−N cross coupling reaction of 3‐alkylidene‐2‐oxindoles with benzene‐1,2‐diamine was explored. Simultaneously, the indoline motif of 3‐alkylidene‐2‐oxindoles as well as 3‐ylidene oxindoles are regioselectively nitrated at the C‐6 position by in‐situ formed NO2 radical. (E)‐3‐(2‐(aryl)‐2‐oxoethylidene)oxindole and (E)‐3‐ylidene oxindole produce distinct nitrated diastereomeric coupling products, a phenomenon influenced by the steric bulk of the functional group. The experimental findings suggest the potential involvement of a radical pathway in this reaction. [ABSTRACT FROM AUTHOR]

Two groups of isomeric imidazothiazolo[1,2,4]triazines and their oxindolylidene derivatives were obtained from 1-alkyl-3-aryl-4,5-dihydroxyimidazolidin-2-(thi)ones. One of the synthesized imidazo[4,5-e]thiazolo[2,3-c][1,2,4]triazine derivatives showed high cytostatic activity at a concentration of 10 μmol/l against four lines of tumor cells: HL-60(TB) (leukemia, –16.1% growth rate), SF-539 (CNS cancer, –2.6% growth rate), MDA-MB-435 (melanoma, –21.2% growth rate), and RXF 393 (kidney cancer, –6.1 % growth rate). [ABSTRACT FROM AUTHOR]

This paper describes a catalytic asymmetric Staudinger-aza-Wittig reaction of (o-azidoaryl)malonates, allowing access to chiral quaternary oxindoles through phosphine oxide catalysis. We designed a novel HypPhos oxide catalyst to enable the desymmetrizing Staudinger-aza-Wittig reaction through the PIII/PV═O redox cycle in the presence of a silane reductant and an IrI-based Lewis acid. The reaction occurs under mild conditions, with good functional group tolerance, a wide substrate scope, and excellent enantioselectivity. Density functional theory revealed that the enantioselectivity in the desymmetrizing reaction arose from the cooperative effects of the IrI species and the HypPhos catalyst. The utility of this methodology is demonstrated by the (formal) syntheses of seven alkaloid targets: (-)-gliocladin C, (-)-coerulescine, (-)-horsfiline, (+)-deoxyeseroline, (+)-esermethole, (+)-physostigmine, and (+)-physovenine.

A reductive cross-coupling strategy for the synthesis of sulfone-containing oxindoles via palladium-catalyzed domino cyclization/alkylsulfonylation reaction of N-substituted arylacrylamides with unactivated alkyl bromides and Na2S2O5 is presented. Moreover, using amines instead of alkyl bromides, a palladium-catalyzed domino cyclization/aminosulfonylation was also established. [ABSTRACT FROM AUTHOR]

A reductive cross-coupling strategy for the synthesis of sulfone-containing oxindoles via palladium-catalyzed domino cyclization/alkylsulfonylation reaction of N-substituted arylacrylamides with unactivated alkyl bromides and Na2S2O5 is presented. Moreover, using amines instead of alkyl bromides, a palladium-catalyzed domino cyclization/aminosulfonylation was also established. [ABSTRACT FROM AUTHOR]

Brønsted acid mediated [3+2] cycloaddition of coumarin‐based enamines with 3‐ylidene oxindoles generated in situ from 3‐hydroxy‐3‐aroylmethyl oxindoles enabled the synthesis of polyheterocyclic compounds with a pyrrolocoumarin core structure in a highly regioselective manner. The synthetic procedure is highly efficient and metal‐free, and no chromatographic purification of the products is required. The chromenopyrrole derivatives bearing an oxindole moiety formed as rapidly interconverting rotamers. [ABSTRACT FROM AUTHOR]

A K2S2O8-mediated direct C(sp2)–C(sp3) bond formation through quinoxalin-2(1H)-ones with oxindoles has been developed. An efficient and feasible strategy for direct C–H functionalization between quinoxalin-2(1H)-ones and oxindoles based on a radical coupling reaction is presented. This methodology provides a concise protocol to obtain 3-(2-oxoindolin-3-yl)quinoxalin-2(1H)-ones in water under mild conditions in moderate to good yields. [ABSTRACT FROM AUTHOR]

The enhancement of 3D character in chemical scaffolds has become an unavoidable space and a key component for diverse applications. Herein, we report a simple phenol-derived catalyst with synergistic involvement of electronic and electrostatic sites to access spirocyclic carbonates from spiroepoxy oxindoles and carbon dioxide. The metal-free and co-catalyst free catalytic system demonstrates excellent activity in synthesizing diverse spirocyclic carbonates with good conversions (up to 99%) under ambient reaction conditions. Volumetric and NMR investigations enabled the synergistic role of the key chemical functionalities in the catalyst and elucidated the probable reaction mechanism. The calculated values of different green metrics revealed the suitability and practical applicability of the catalytic system. [ABSTRACT FROM AUTHOR]

We here report an effective NHC‐catalyzed acylation of 2‐oxindoles using aldehydes with the aid of aerobic oxidation to prepare 3‐alkylideneoxindoles ‐ a biologically active moiety. This protocol is the first report on the use of oxidized Breslow intermediate for the carbon nucleophile and applies to a wide variety of aryl aldehydes, cyclohexanal, and metallocene‐aldehyde. Lower catalyst loading, milder base, greener oxidant, easily available substrates, and ambient reaction temperature exemplify this as a sustainable methodology. [ABSTRACT FROM AUTHOR]

A sequential one‐pot direct strategy for the synthesis of 2‐hydroxy‐2‐substituted‐2H‐benzo[b][1,4]oxazin‐3(4H)‐ones is developed under ambient conditions with moderate to good yields (up to 75 %) by regioselective ring‐opening of spiro‐epoxy/aziridine oxindoles with 50 % aq. H2O2 followed by rearrangement reaction in presence of amberlyst‐15 catalyst. Further, sequential reaction with aldehydes/ketones and carbonyldiimidazole (CDI) gave spiro[benzo[b][1,4]oxazine‐2,4′‐[1,3]dioxolan]‐3(4H)‐ones and spiro[benzo[b][1,4]oxazine‐2,4′‐[1,3]dioxolane]‐2′,3(4H)‐diones, respectively. [ABSTRACT FROM AUTHOR]

Indolyl thioethers and indolin‐2‐one motifs are extremely common in pharmaceuticals and organic materials, therefore developing a method to create these scaffolds is considered to be a vital endeavour in the chemical sciences. Here we have reported a unified strategy developed by the fine‐tuning of catalyst‐solvent combination [SOCl2 /AlCl3 in CHCl3 and SOCl2/DMSO (1 : 1) in CHCl3 at 25 °C] towards selective functionalization of Indole to synthesize 2,2′‐thiobisindoles and 3‐chloro‐3‐alkyl substituted oxindoles selectively in one‐pot manner with good to satisfactory yield (52‐86 %; 26 Examples). In application, reactions of 3‐subsituted indole and isatin derivatives produced the 1‐(chloromethyl) indoline‐2,3‐diones by just changing the reaction condition (60 °C), which shows the synthetic utility of the developed method. [ABSTRACT FROM AUTHOR]

A sustainable and efficient strategy for the synthesis of 3-pyridyl-3,3-disubstituted oxindole derivatives has been achieved via PyBroP (bromotripyrrolidinophosphonium hexafluorophosphate) promoted nucleophilic addition reaction of oxindoles with pyridine N-oxides. The approach worked well under relatively mild conditions. The protocol features a broad substrate scope and good functional group tolerance and gives products in moderate to excellent (52–95%) yields. [ABSTRACT FROM AUTHOR]

The Hauser‐Kraus (H−K) annulation of N‐unsubstituted 3‐olefinic oxindoles with 3‐nucleophilic phthalides triggers a cascade of ring expansion and ring contraction reactions through several regioselective steps in one pot. While oxazepines were isolated in the presence of stoichiometric amounts of base at room temperature, carbazoles and phenanthridinediones were the products in the presence of excess base and microwave irradiation. Mechanistic studies guided by stepwise reactions and control experiments revealed that the isolable oxazepine intermediate, formed via ring expansion of the H−K adduct, is the key precursor to carbazole and phenanthridinedione via decarboxylative regioselective cyclizations. [ABSTRACT FROM AUTHOR]

Fluorine-containing moieties are of great interest in the development of new synthetic methods due to their considerable medicinal value. Thus, researchers have explored direct trifluoroethylation using CF3CH2-containing precursors; however, the high cost, prolonged synthesis time, toxic nature, and instability towards transition metal catalysis of these precursors pose challenges. As an alternative, conducting trifluoroethylation by in situ production of 2,2,2-trifluorodiazoethane (CF3CHN2) from CF3CH2NH2·HCl in solution is a comparatively easy, safe, and greener approach. However, previous reports using 2,2,2-trifluorodiazoethane in solution also demonstrate the use of transition metal-catalyzed pathways under harsh reaction conditions and hazardous solvents. Herein, we have developed a triflic acid (a commercially available and cheap Brønsted acid) catalyzed protocol for O-trifluoroethylation of 3,3-disubstituted, monosubstituted, unsubstituted, and chalcone-based oxindoles and isoindolines, and S-trifluoroethylation of thio-oxindoles in the presence of in situ generated 2,2,2-trifluorodiazoethane in solution. This highly efficient metal- and additive-free strategy offers a mild and feasible approach to achieve chemoselective trifluoroethylation with good to excellent yields in a very short reaction time (10 minutes). This methodology has a broad substrate scope, making it a versatile approach that can be effectively employed for all types of cyclic amides. Additionally, the method is scalable for larger operations. The calculation of various green chemistry metrics, such as high atom economy (93%), high carbon efficiency (100%), high reaction mass efficiency (74%), and low E-factor(0.40 kg waste per kg product), confirms the eco-friendliness of this approach. The EcoScale evaluation showcases the simplicity, effectiveness, and eco-friendliness of this approach. [ABSTRACT FROM AUTHOR]

Oxindoles are prevalent structures in natural products and pharmaceutically active molecules. To support structure–activity‐relationship (SAR) studies in a medicinal chemistry program, we developed a straightforward and scalable synthesis route to 1‐aminoethyl oxindole building blocks harboring various types of substituents. Our strategy relies on an intramolecular Buchwald–Hartwig amidation of a 2‐bromophenylacetic amide precursor. The cyclization substrates can be prepared from readily available benzaldehydes by ortho‐selective C(sp2)−H bromination followed by homologation to the corresponding phenylacetic acid derivatives. The process was optimized to allow for preparation of 246 g of one representative example. [ABSTRACT FROM AUTHOR]

This article provides information on the synthesis of oxindoles, which are aromatic heterocyclic compounds with diverse biological activities. The authors explore different synthetic methods for preparing oxindoles, focusing on the reduction of 2-nitrophenylacetic acids using samarium diiodide (SmI2) under neutral conditions. They conducted experiments to optimize the reaction conditions and found that 6.5 equivalents of SmI2 at 60°C yielded the best results. The article also includes detailed procedures for the preparation of 2-nitrophenylacetic acids, which are used as starting materials in the synthesis. Additionally, the document provides a detailed account of the synthesis and characterization of various 1,3-dihydro-2H-indol-2-one derivatives, including specific information about yields, melting points, and spectral data for each compound. Finally, the text presents chemical data for various compounds, including their NMR spectra, HRMS data, and purification methods, which can be useful for researchers studying these compounds. [Extracted from the article]

A series of tryptamine derivatives were transformed into their corresponding 3‐chloro‐2‐oxidation products under simple and mild conditions. This protocol is an operationally simple system that utilizes a single reagent SO2ClF plays a dual role as both oxidant and chloride source and enables the construction of various 3,3‐disubstituted oxindoles with good functional group tolerance. The transformations of the product highlight its potential synthetic applications. [ABSTRACT FROM AUTHOR]

Transition metal-free carbonyl directed boron-Wittig reaction of α-bis(boryl)carbanions with the corresponding isatins or with the α-keto esters/amides was achieved to access alkenyl oxindoles in good yield and high stereoselectivity. [ABSTRACT FROM AUTHOR]

We herein report a protocol for the α‐thio‐ and α‐seleno‐cyanation of different cyclic β‐ketoesters and oxindoles by using NaSCN or KSeCN as easily accessible inorganic nucleophilic S(e)CN sources under oxidative conditions. Key to success for both transformations is the use of dibenzoylperoxide as an oxidant allowing for the coupling of two inherently nucleophilic species under operationally simple conditions in high yields and with broad functional group tolerance. [ABSTRACT FROM AUTHOR]

An efficient heterogeneous silver‐catalyzed α‐alkylation of nitriles and oxindoles using alcohols via borrowing hydrogen strategy has been developed for the first time. The active nanostructured material, namely [Ag/Mg4Al‐LDH], composed by silver nanoparticles (3‐4 nm average particle size) homogeneously stabilized onto a [Mg4Al‐LDH] support with suitable Brønsted basic properties, constitutes a stable catalyst for the sustainable building of novel C−C bonds from alcohols and C‐nucleophiles. By applying this catalyst, a broad range of α‐functionalized nitriles and oxindoles has been accessed with good to excellent isolated yields and without the addition of external bases. Moreover, the novel silver nanocatalyst has also demonstrated its successful application to the cyclization of N‐[2‐(hydroxymethyl)phenyl]‐2‐phenylacetamides to afford 3‐arylquinolin‐2(1H)‐ones, through a one‐pot dehydrogenation and intramolecular α‐alkylation. Control experiments, kinetic studies, and characterization data of a variety of [Ag/LDH]‐type materials confirmed the silver role in the dehydrogenation and hydrogenation steps, while [Mg4Al‐LDH] matrix is able to catalyze condensation. Interestingly, these studies suggest as key point for the successful activity of [Ag/Mg4Al‐LDH], in comparison with other [Ag/LDH]‐type nanocatalysts, the suitable acid‐base properties of this material. [ABSTRACT FROM AUTHOR]

This article explores the application of cascade reactions in synthetic chemistry, specifically focusing on Pd-catalyzed intramolecular cyclization-thiocarbonylation cascades using thioesters. Thioesters are important in organic syntheses and can be converted into various compounds. The study investigates the use of thioacetate as an alternative to TIPS thioether in the cascade reaction, emphasizing the importance of distinguishing the desired product. The results of the study demonstrate high yields of chromane, coumaran, indoline, and oxindole derivatives with a chiral quaternary carbon atom, achieved through the use of AcSPh and Cs2CO3. The reaction time was significantly reduced, and the use of thioesters improved atom economy and cost effectiveness. The findings suggest potential applications in constructing other fused-ring systems. [Extracted from the article]

This article explores the synthesis of oxindole derivatives, which are important compounds in organic and medicinal chemistry. The authors present a method for synthesizing these compounds using continuous-flow technology, which offers advantages over traditional batch methods. Through experimentation, the authors optimized the reaction parameters and achieved high conversion rates and yields. The results suggest that continuous-flow technology has the potential for large-scale production of oxindole derivatives in a fast and cost-effective manner. The article also discusses the synthesis of 3-alkyloxindoles through reductive alkylation, providing detailed experimental procedures and characterization data for the synthesized compounds. The research was supported by grants from the European Union. [Extracted from the article]

An efficient methodology has been developed for the synthesis of 3,3‐di(indolyl)oxindoles and bis(indolyl)methanes under mild conditions. The efficient condensation reaction of indoles with isatin and aldehyde led to the corresponding derivatives in the presence of silver molybdate (Ag‐PMo12) nanocomposite and aqueous medium. In addition, the silver‐doped catalytic system enables the one‐pot formation of diindolyl derivatives with excellent yields, short reaction times and under environmental benign conditions. [ABSTRACT FROM AUTHOR]

Herein, we introduce a photocatalyst- and additive-free method for the preparation of valuable 3,3-disubstituted oxindoles bearing trifluoromethyl alcohol moieties from readily available acrylamides and cheap trifluoropyruvates. The excited trifluoropyruvates under ultraviolet-light irradiation react efficiently with acrylamides delivering a variety of trifluoromethyl oxindoles with broad functional group tolerance and moderate to good yields. This protocol features mild reaction conditions, simple operation and ready scalability. [ABSTRACT FROM AUTHOR]

Keywords: N-heterocyclic carbene; regioselective addition; allene; organocatalysis; plant protection EN N-heterocyclic carbene regioselective addition allene organocatalysis plant protection 1997 2000 4 10/09/23 20231024 NES 231024 Graph Allene scaffolds are frequently found in natural products, medicines, and agrichemicals with proven biological activities. Compared with the precatalyst B A b , other aminoindanol-derived NHC catalysts bearing I N i -Ph, [39] I N i -C SB 6 sb F SB 5 sb , [40] and I N i -C SB 6 sb H SB 2 sb Cl SB 3 sb [41] (C SB 6 sb H SB 2 sb Cl SB 3 sb = 1,3,5-trichlorophenyl) gave the target product B 3a b in lower yields and diastereoselectivities (e.g., entries 2-4). Although impressive success has been achieved in the construction of allene frameworks, [23] the development of highly efficient and regioselective methods for quick synthesis of allene derivatives is still challenging. A nucleophilic addition of ROH to intermediate B III b provides the allene product B 3a b , with the regeneration of NHC catalyst for additional catalytic cycles. [Extracted from the article]

A direct oxidative alkylarylation reaction of N-arylacrylamides with simple alkanes for the synthesis of 3,3-disubstituted oxindoles under metal-free conditions was demonstrated. By using PhI(OAc)2 [(diacetoxy)iodobenzene] as an oxidant, a series of 3,3-disubstituted oxindoles bearing different aryl or alkyl substituents were generated in moderate to excellent chemical yields via a radical-initiated alkylation/cyclization process. The reported method features good functional group tolerance and wide substrate range, and provides an effective method for the preparation of various alkyl substituted 3,3-disubstituted oxindoles.

Comprehensive Summary: A new electrophilic monofluoromethylthiolating reagent N‐fluoromethylthiophthalimide PhthSCH2F 1 was developed. Reagent 1 could be readily synthesized from easily available starting materials benzyl mercaptan and CH2FCl in three steps. N‐Fluoromethylthiophthalimide 1 is a powerful electrophilic monofluoromethylthiolating reagent that allows the monofluoromethylthiolation of a wide range of nucleophiles including alkynes, aryl/vinyl boronic acids, electron‐rich heteroarenes, β‐ketoesters and oxindoles, as well as thiols under mild conditions. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: A new electrophilic monofluoromethylthiolating reagent N‐fluoromethylthiophthalimide PhthSCH2F 1 was developed. Reagent 1 could be readily synthesized from easily available starting materials benzyl mercaptan and CH2FCl in three steps. N‐Fluoromethylthiophthalimide 1 is a powerful electrophilic monofluoromethylthiolating reagent that allows the monofluoromethylthiolation of a wide range of nucleophiles including alkynes, aryl/vinyl boronic acids, electron‐rich heteroarenes, β‐ketoesters and oxindoles, as well as thiols under mild conditions. [ABSTRACT FROM AUTHOR]

Fluorinated oxindoles are frequently used building blocks in asymmetric synthesis and represent an important scaffold found in a variety of biologically relevant compounds. While it is understood that incorporation of fluorine atoms into organic molecules can improve their pharmacological properties, the impact on the configurational stability of chiral organofluorines is still underexplored. In this study, semipreparative HPLC enantioseparations of five oxindoles were carried out, and the resulting enantiomerically enriched solutions were used to investigate base promoted racemization kinetics at room temperature. It was found that incorporation of fluorine at the chiral center increases the configurational stability, while substitutions on the aromatic ring and at the lactam moiety also have significant effects on the rate of racemization, which generally follows reversible first‐order reaction kinetics. [ABSTRACT FROM AUTHOR]

Due to its excellent bioactivity profile, which is increasingly utilized in pharmaceutical and synthetic chemistry, spirooxindole is an important core scaffold. We herein describe an efficient method for the construction of highly functionalized new spirooxindolocarbamates via a gold‐catalyzed cycloaddition reaction of terminal alkynes or ynamides with isatin‐derived ketimines. This protocol has a good functional group compatibility, uses readily available starting materials, mild reaction conditions, low catalyst loadings and no additives. It enables the transformation of various functionalized alkyne groups into cyclic carbamates. Gram‐scale synthesis was achieved and DFT calculations verify the feasibility of the mechanistic proposal. Some of the target products exhibit good to excellent antiproliferative activity on human tumor cell lines. In addition, one of the most active compounds displayed a remarkable selectivity towards tumor cells over normal ones. [ABSTRACT FROM AUTHOR]

Visible‐light‐induced photoreaction of carboranes is an effective approach to prepare carborane‐containing compounds. While several methods involving boron‐centered carboranyl radicals have been established, those for carbon‐centered carboranyl radicals are underdeveloped, except for the UV‐light‐promoted photohomolysis. Herein, we describe a simple but effective approach to access carbon‐centered carboranyl radicals by photoreduction of carborane phosphonium salts under blue light irradiation without using transition metals and photocatalysts. The utility of the method was demonstrated by successfully preparing a range of carborane‐oxindole‐pharmaceutical hybrids by radical cascade reactions. Computational and experimental studies suggest that the carbon‐centered carboranyl radicals are generated by single‐electron transfer of the photoactive charge‐transfer complexes between the salts and the additive potassium acetate. [ABSTRACT FROM AUTHOR]