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Complementary to the design of a single structurally complex chiral ligand to promote each step in transition‐metal catalysis, multiligand relay catalysis through dynamic ligand exchange with each step in the catalytic cycle promoted by its best ligand provides an attractive approach to enhance the whole reaction reactivity and selectivity. Herein, a regio‐ and enantioselective NiH‐catalyzed migratory hydroarylation process with a simple combination of a chain‐walking ligand and an asymmetric arylation ligand, producing high‐value chiral α‐(hetero)aryl‐substituted amines and their derivatives under mild conditions, is reported. The potential synthetic applications of this transformation are demonstrated by the concise synthesis of (S)‐nicotine and a CDK8 inhibitor. [ABSTRACT FROM AUTHOR]

A CuInS2 quantum dot-modified K-C3N4 Z-scheme heterojunction was designed and synthesized. The structure and composition of CuInS2/K-C3N4 were well characterized. The arylation of heteroarenes with aryl diazonium salts driven by a heterogeneous CuInS2/K-C3N4 catalytic system was established under visible light irradiation in water for the first time. A variety of arylated heteroarenes were synthesized in high yields with commendable functional group tolerance. The designed CuInS2/K-C3N4 photocatalyst can be recycled and reused several times without significantly reducing its catalytic activity. [ABSTRACT FROM AUTHOR]

A C(sp3)−H bond arylation of aliphatic amides has been achieved via organophotoredox catalysis. The reaction could be realized at room temperature with visible light source and metal‐free catalyst. Quinuclidine is employed as an efficient HAT reagent and a range of aliphatic amides is employed as both substrate and solvent in the reaction. This photocatalyzed transformation provides a convenient protocol to afford a board range of N‐benzyl amides. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The azepine ring is a prominent structural scaffold in biologically significant molecules. In this study, we present a Ni(II)‐catalyzed asymmetric difunctionalization of alkynes, involving intermolecular regioselective arylation and intramolecular nitrile addition, enabling the synthesis of enantioenriched azepine derivatives. This reaction simultaneously installs an all‐carbon quaternary stereocenter and introduces an unprotected imine functionality, showing great promise for subsequent transformations. The reaction exhibits good tolerance toward various functional groups, resulting in high yields and enantioselectivities. The synthetic utility of this methodology is further demonstrated through gram‐scale synthesis and product derivatization. This research offers an efficient approach to the synthesis of seven‐membered nitrogen heterocycles. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Herein, we report nickel‐catalyzed cross‐coupling of gem‐difluorinated cyclopropanes with boronic acids, providing the corresponding arylated 2‐fluoroallylic scaffolds. This approach used commercially available phosphine ligand Xantphos to obtain monofluorinated alkenes with high regioselectivity and Z‐stereoselectivity. Mechanistic studies proposed a Ni(II)‐fluoroallyl pathway and excluded the radical pathway. Meanwhile, DFT study of the reductive elimination clarified the origin of the high linear selectivity. [ABSTRACT FROM AUTHOR]

We report the triply selective and sequential diversification of a single Csp3 carbon carrying Cl, Bpin and GeEt3 for the modular and programmable construction of sp3‐rich molecules. Various functionalizations of Csp3−Cl and Csp3−BPin (e.g. alkylation, arylation, homologation, amination, hydroxylation) were tolerated by the Csp3−GeEt3 group. Moreover, the methodological repertoire of alkyl germane functionalization was significantly expanded beyond the hitherto known Giese addition and arylation to alkynylation, alkenylation, cyanation, halogenation, azidation, C−S bond formation as well as the first demonstration of stereo‐selective functionalization of a Csp3‐[Ge] bond. [ABSTRACT FROM AUTHOR]

We report the synergistic combination of Pd(OAc)2 and Ag2O for the oxidative C−H arylation of (poly)fluoroarenes with aryl pinacol boronates (Ar‐Bpin) in DMF as the solvent. This procedure can be conducted easily in air, and without using additional ligands, to afford the fluorinated unsymmetrical biaryl products in up to 98 % yield. Experimental studies suggest that the formation of [PdL2(C6F5)2] in DMF as coordinating solvent does not take place under the reaction conditions as it is stable to reductive elimination and thus would deactivate the catalyst. Thus, the intermediate [Pd(DMF)2(ArF)(Ar)] must be formed selectively to give desired arylation products. DFT calculations predict a low barrier (5.87 kcal/mol) for the concerted metalation deprotonation (CMD) process between C6F5H and the Pd(II) species formed after transmetalation between the Pd(II)X2 complex and aryl‐Bpin which forms a Pd‐Arrich species. Thus a Pd(Arrich)(Arpoor) complex is generated selectively which undergoes reductive elimination to generate the unsymmetrical biaryl product. [ABSTRACT FROM AUTHOR]

The present work represents a novel methodology for the selective arylation of coumarin‐3‐carboxylates with arylboronic acids via a photochemical route, marking the first‐ever attempt for the direct alkenyl C−H arylation using rose bengal as a photocatalyst, which is a readily available and cost‐effective alternative to transition metal catalysis. The reaction proceeds smoothly in MeOH/H2O solvent media in the presence of radical initiator affording the arylated products in good yields (60–80 %). The reaction parameters such as visible light, radical initiator, oxidant, anhydrous solvent, and inert atmosphere play a crucial role for the success of this methodology. The substituents present on the substrate show a significant effect on the conversion. This study provides a valuable contribution to the field of organic synthesis offering a new and efficient approach to the arylation of coumarin‐3‐carboxylic acid esters with a broad substrate scope and high functional group tolerance. It is a versatile method and provides a direct access to biologically relevant 4‐arylcoumarin‐3‐carboxylates. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The azepine ring is a prominent structural scaffold in biologically significant molecules. In this study, we present a Ni(II)‐catalyzed asymmetric difunctionalization of alkynes, involving intermolecular regioselective arylation and intramolecular nitrile addition, enabling the synthesis of enantioenriched azepine derivatives. This reaction simultaneously installs an all‐carbon quaternary stereocenter and introduces an unprotected imine functionality, showing great promise for subsequent transformations. The reaction exhibits good tolerance toward various functional groups, resulting in high yields and enantioselectivities. The synthetic utility of this methodology is further demonstrated through gram‐scale synthesis and product derivatization. This research offers an efficient approach to the synthesis of seven‐membered nitrogen heterocycles. [ABSTRACT FROM AUTHOR]

This article explores the synthesis of N-arylated triazole derivatives using ligand-free copper catalysts. The authors optimize the reaction conditions and find that using CuCl as the catalyst, K3PO4 as the base, and DMF as the solvent yields the highest product yield. The study also investigates the substrate scope and finds that certain substitutions lead to higher yields. This research provides valuable insights into the synthesis of important compounds with potential pharmaceutical applications. The article acknowledges the support of the National Institute of Education, Singapore. [Extracted from the article]

Herein we report a method for the synthesis of thioethers by forging C(aryl)‐S bond via an aryne mechanism. The active aryne species can be generated from o‐diiodoarenes and NaH in THF at room temperature, then lead to the arylations of a wide range of aryl thiols and thioureas. Different from transition metal‐catalyzed cross‐coupling reactions, no disubstituted byproduct is formed in our protocol. The o‐iodoaryl thioether products are intermediates that could be transformed into pharmaceutically interesting molecules. [ABSTRACT FROM AUTHOR]

A light-induced method is developed for synthesizing azauracils. This method is independent from traditional methodology. Remarkably, this reaction can also be powered by sunlight. The applicability of this method is further demonstrated through its successful implementation in large-scale reactions and its use in synthesizing derivatives. [ABSTRACT FROM AUTHOR]

A four-step synthesis process of bifunctional, noncovalent organocatalysts based on the chiral (1R,2R)-cyclohexane-1,2-diamine scaffold containing a 1,2-benzenediamine H-bond donor was developed. Nucleophilic aromatic substitution of the 2-fluoronitrobenzene derivative with the commercial (1R,2R)-cyclohexane-1,2-diamine was followed by selective alkylation of the primary amino group, reduction of the aromatic nitro group and final derivatization of the primary aromatic amino group, i.e., acylation, sulfonation, reductive alkylation and arylation, leading to the four subtypes of organocatalysts. All new compounds were fully characterized. The prepared organocatalysts (32 examples) were tested in the Michael addition of acetylacetone to trans-β-nitrostyrene, yielding the addition product with incomplete conversions (up to 93%) and enantioselectivities of up to 41% ee. [ABSTRACT FROM AUTHOR]

An efficient method for the synthesis of 1-substituted 5-aryl-1,2,4-triazoles by selective C—H arylation of 1-substituted 1,2,4-triazoles with non-activated aryl chlorides and aryl bromides under the catalysis by a palladium complex with a N-heterocyclic carbene ligand IPr*OMe using 1,1,2,2-tetraphenylethane-1,2-diol (TPEDO) as a catalyst activator is reported. [ABSTRACT FROM AUTHOR]

Carbo- and heterocycles are frequently used as crucial scaffolds in natural products, fine chemicals, and biologically and pharmaceutically active compounds. Transition-metal-catalyzed cyclization of 1,6-enynes has emerged as a powerful strategy for constructing functionalized carbo- and heterocycles. Despite significant progress, the regioselectivity of alkyne functionalization is entirely substrate-dependent. And only exo-cyclization/cross-coupling products can be obtained, while endo-selective cyclization/cross-coupling remains elusive and still poses a formidable challenge. In this study, we disclose a nickel-catalyzed switchable arylation/cyclization of 1,6-enynes in which the nature of the ligand dictates the regioselectivity of alkyne arylation, while the electrophilic trapping reagents determine the selectivity of the cyclization mode. Specifically, using a commercially available 1,10-phenanthroline as a ligand facilitates trans-arylation/cyclization to obtain seven-membered ring products, while a 2-naphthyl-substituted bisbox ligand promotes cis-arylation/cyclization to access six-membered ring products. Diastereoselective cyclizations have also been developed for the synthesis of enantioenriched piperidines and azepanes, which are core structural elements of pharmaceuticals and natural products possessing important biological activities. Furthermore, experimental and density functional theory studies reveal that the regioselectivity of the alkyne arylation process is entirely controlled by the steric hindrance of the ligand; the reaction mechanism involves exo-cyclization followed by Dowd-Beckwith-type ring expansion to form endo-cyclization products. Divergent functionalizations of pi bonds allow for synthetic chemists to move from simplicity to complexity. Here, the authors report a nickel-catalyzed switchable arylation/cyclization of 1,6-enynes in which the nature of the ligand dictates the regioselectivity of alkyne arylation, while the electrophilic trapping reagents determine the selectivity of the cyclization mode. [ABSTRACT FROM AUTHOR]

A palladium-catalyzed asymmetric α-arylation of N-carbamoyl imine precursors containing CCl3, CF3 and CF2H is presented. This protocol provides facile access to a series of chiral α-aryl trichloroethylamines bearing various functional groups, with moderate to high yields (40–82% yield) and high enantioselectivity (80–99% ee). [ABSTRACT FROM AUTHOR]

Cu(II)-catalyzed N-arylation of electron-deficient NH-heterocycles 'in-water' at room temperature is described. A wide substrate scope with respect to structural and electronic variation of NH-heterocycles plus arylboronic acids allows product diversity. The functional group tolerance, 'gram-scale' synthesis, synthetic elaboration of N-arylated products and late-stage arylation are the distinct advantages. [ABSTRACT FROM AUTHOR]

Distyrylbenzenes (DSBs) are well‐known for their strong multicolour fluorescence. Fluorescence tuning of DSB via further functionalization/arylation, on the other hand, is uncommon. This paper reports a Pd‐catalysed direct arylation approach for introducing different aryl groups onto fluorobenzene‐containing DSB moiety (7) in high yields (67–72 %). The versatile methodology allows the substitution of neutral [tolyl (1)], electron‐deficient [p‐formyl benzene (2), p‐acetyl benzene (3), p‐nitrobenzene (4)] and electron‐rich [carbazole (5), triphenylamine (6)] aryl groups. The electron‐deficient aryls render mono‐substitution, while the electron‐rich counterparts promote di‐substitution. The compounds (1–6) show blue, green, and yellow fluorescence in both the solution and solid states; the fluorescence quantum yields reach >98 % and the peak maxima span from 425 to 560 nm. The mono‐carbazole DSB (5) exhibit white light emission (WLM) in polar solvents (acetone, DMF, CH3CN, DMSO and NMP) with very high fluorescence quantum yields (φf) of 60–80 %. For WLM, such high efficiency (φf) is somewhat uncommon. Moreover, visible‐to‐NIR reversible electrochromism is demonstrated by the TPA‐integrated DSB (6). The colour of 6 changes from pristine light yellow to orange, and the absorption maxima shifts from 372 to 1500 nm when a positive potential of 1.0 V vs Ag/Ag+ is applied. Moreover, the system shows high colouration efficiency in the NIR region with fast switching speeds for colouration and decolouration as fast as 0.98 s and 1.05 s. [ABSTRACT FROM AUTHOR]

We describe an efficient and versatile method for the direct C−H arylation of xanthines with aryl halides using Pd/P(o‐tolyl)3 as catalyst and Ag2O as an additive. Silver salts have been frequently used as an additive in the Pd‐catalyzed C−H bond activation reactions albeit in excessive amounts (2 to 4 eq.). Herein, we use of a stoichiometric amount (0.1 to 1 eq.) of Ag2O to obtain the optimum yields of C‐8 arylated products. This method exhibits broad substrate scope and enables synthesis of a wide range of xanthine derivatives by variation of aryl component at the C‐8 position. A key advantage of silver additive is that it reduces the catalyst loading and time required for the completion of reactions. Although kinetic experiments show that the inclusion of silver salt accelerates the rate of reaction, catalytic role of silver salt could not be conceived since the C−H bond cleavage is not a rate determining step. Silver salt presumably act as a terminal oxidant in the catalytic cycle and assist the regeneration of Pd catalyst. Moreover, preliminary assessment of biological activities of xanthines demonstrates that the C‐8 arylated xanthines derivatives efficiently inhibit the α‐Synuclein fibrillation, a key factor behind Parkinson's disease. [ABSTRACT FROM AUTHOR]

A low pKa (5.2), high polarizable volume (3.8 Å), and proneness to oxidation under ambient conditions make selenocysteine (Sec, U) a unique, natural reactive handle present in most organisms across all domains of life. Sec modification still has untapped potential for site‐selective protein modification and probing. Herein we demonstrate the use of a cyclometalated gold(III) compound, [Au(bnpy)Cl2], in the arylation of diselenides of biological significance, with a scope covering small molecule models, peptides, and proteins using a combination of multinuclear NMR (including 77Se NMR), and LC–MS. Diphenyl diselenide (Ph−Se)2 and selenocystine, (Sec)2, were used for reaction optimization. This approach allowed us to demonstrate that an excess of diselenide (Au/Se−Se) and an increasing water percentage in the reaction media enhance both the conversion and kinetics of the C−Se coupling reaction, a combination that makes the reaction biocompatible. The C−Se coupling reaction was also shown to happen for the diselenide analogue of the cyclic peptide vasopressin ((Se−Se)‐AVP), and the Bos taurus glutathione peroxidase (GPx1) enzyme in ammonium acetate (2 mM, pH=7.0). The reaction mechanism, studied by DFT revealed a redox‐based mechanism where the C−Se coupling is enabled by the reductive elimination of the cyclometalated Au(III) species into Au(I). [ABSTRACT FROM AUTHOR]

Development of new chiral ligands is essentially important in the field of asymmetric metal catalysis. Bispidines, steming from natural alkaloids, represent an intriguing yet underexplored class of chiral ligands. In this article, we developed a series of bispidine‐based chiral ligands with chirality locked in the side chain, and explore their properties by applying in the palladium‐catalyzed asymmetric addition of arylboric acids to cyclic N‐sulfonyl ketimines. A S,N‐bispidine ligand was found especially efficient, affording a series of chiral benzosultams with a quaternary chiral center in excellent yields with excellent ee values. Density functional theory (DFT) calculations and crystal structure of catalyst helped to propose a reasonable mechanism including a possible transition state model to explain the origin of stereoselectivity. [ABSTRACT FROM AUTHOR]

Di- and triarylmethanes are an important class of compounds in many fields. Here, we report an efficient light-induced arylation (alkylation) for the synthesis of diarylmethanes, bis(diarylmethyl)benzenes, arylalkylmethanes, and triarylmethanes from readily accessible N-sulfonylhydrazones and aryl/alkylboronic acids with the aid of Cs2CO3. In the presence of light, the synthesis of diarylmethanes was also achieved from aldehydes in a one-pot manner via a three-component approach in good yields. Furthermore, we have demonstrated the synthetic utility by synthesizing organoboron compounds and 2°-alcohol. [ABSTRACT FROM AUTHOR]

A Pd‐catalyzed heterocyclization/carbonylation/arylation cascade reaction between β,γ‐unsaturated N−Ts hydrazones and commercially available arylboronic acids as coupling partners is described, producing 2‐pyrazoline‐ketone derivatives in 11–78% yield. A detailed statistical analysis of reactivity patterns of boronic acids provided key information about the limitations of the method, highlighting the challenges of degradation pathways. Our methodology offers a tool for synthesizing diverse 2‐pyrazoline‐ketone derivatives, expanding the toolbox of accessible N−N‐heterocycles. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The rapid synthesis of structurally complicated electron donors & acceptors still remains a major challenge in organic solar cells (OSC). In this work, we developed a highly efficient strategy to access long‐chain oligomeric donor and acceptors for OSC applications. A series of cyclopentadithiophene (CPDT) and benzothiadiazole (BT)‐based π‐conjugated oligomers, i.e., three oligomeric acceptors (BTDT)n‐IC (n = 1—3) and one long‐chain oligomeric donor (BTDT)4‐RD, are facilely synthesized by an atom‐ and step‐economical, and labor‐saving direct C—H arylation (DACH) reaction (i.e., C—H/C—Br cross coupling). Note that (BTDT)4‐RD involving five CPDT, four BT and two rhodamine (RD) building blocks is the longest oligomeric donor in the fullerene‐free OSC devices ever reported. The dependence of the structure‐property‐performance correlation of (BTDT)n‐IC (n = 1—3) and (BTDT)4‐RD on the π‐conjugation lengths is thoroughly investigated by opto‐electrochemical measurements, bulk heterojunction (BHJ) OSC devices and microscopies. The (BTDT)1‐IC:PBDB‐T and (BTDT)4‐RD:Y6 BHJs achieve power conversion efficiencies of 9.14% and 4.51%, respectively. Our findings demonstrate that DACH reaction is a powerful tool to tune the opto‐electronic properties and device performances by regulating the lengths of π‐conjugated oligomers with varied numbers of repeating units. [ABSTRACT FROM AUTHOR]

Disubstituted isothiazolo[4,3-b]pyridines are known inhibitors of cyclin G-associated kinase. Since 3-substituted-7-aryl-isothiazolo[4,3-b]pyridines remain elusive, a strategy was established to prepare this chemotype, starting from 2,4-dichloro-3-nitropyridine. Selective C-4 arylation using ligand-free Suzuki-Miyaura coupling and palladium-catalyzed aminocarbonylation functioned as key steps in the synthesis. The 3-N-morpholinyl-7-(3,4-dimethoxyphenyl)-isothiazolo[4,3-b]pyridine was completely devoid of GAK affinity, in contrast to its 3,5- and 3,6-disubstituted congeners. Molecular modeling was applied to rationalize its inactivity as a GAK ligand. [ABSTRACT FROM AUTHOR]

Herein, we report the synthesis of four new palladium complexes containing a benzimidazole core and examine their catalytic activities in the direct arylation of heteroaromatic species with aryl bromides. The complexes were characterized by 1H and 13C NMR spectroscopy, FT-IR spectroscopy, and elemental analysis. In the 13C NMR spectra, NCHN peaks of Pd(II) complexes were observed between 143.2 and 144.9 ppm. Also, the structure of 2b was determined by single-crystal XRD analysis. The obtained data suggest that the lengths of the Pd–N and Pd–Cl bonds are like those of previous Pd complexes. Direct arylation reactions, using KOAc as base and DMAc as solvent under inert conditions, were carried out with the synthesized complexes in the presence of various aryl bromides, and 2-acetylthiophene, 2-furaldehyde, and 1-methylpyrole-2-carboxaldehyde. Moderate to high yields were obtained under 1% mol catalyst loading conditions. The results showed that electron-donating and electron-withdrawing substituents on the aryl halides may produce coupling products in good yields in the presence of 2a–d. These findings contribute to the synthesis and design of palladium complexes containing benzimidazole cores. [ABSTRACT FROM AUTHOR]

A method of stereodivergent intramolecular ring‐opening arylation of amine‐tethered epoxides to 3,4‐disubstituted tetrahydroquinolines has been developed. The tuneable good stereoselectivity was attained by changing the catalyst from titanocene(III) catalyst to Lewis‐acidic zinc catalyst. [ABSTRACT FROM AUTHOR]

A novel strategy for the synthesis of 6‐methyl benzofuro[3,2‐c] quinoline derivatives via copper‐catalyzed dehydrogenative CO arylation has been presented. Optimization studies have been carried out by varying various catalysts, bases, solvents, and other physical parameters. Keeping use of this dehydrogenative cross‐coupling CO arylation reaction, a variety of bioactive building blocks like fused benzofuro quinoline heterocycles were smoothly assembled in moderate to higher yields. [ABSTRACT FROM AUTHOR]

Anions of carboxylic acids are widely used as the promoters of ruthenium-catalyzed reactions of C—H activation of substrates containing an N-donar directing group. The promoting effect of structure of anions of aliphatic and (hetero)aromatic carboxylic acids on the C—H arylation of benzene, furan, and thiophene rings in benzo[d]imidazol-2-yl-(hetero)arenes, wherein the benzimidazole moiety played the role of N-donor directing group, was evaluated. It was found that the structural effect of carboxylate anion on the efficiency of promotion of the catalytic system can significantly vary upon the arylation of different substrates. Adamantane-1-carboxylic acid was proposed as the most effective and universal promoter, based on which a new efficient catalytic system was developed for the selective arylation of benzo[d]imidazol-2-yl-(hetero)arenes. [ABSTRACT FROM AUTHOR]

The conversion of commercially available chiral sulfinamides into pharmaceutically useful chiral sulfoximines via direct SIV-functionalization is synthetically attractive but challenging due to the competitive reaction of N-functionalization. Herein, we disclose a novel strain-release strategy to access stereospecific and chemoselective SIV-arylation and alkenylation of sulfinamides using arynes and strained cyclic alkynes. This method tolerates an unprecedented chemical diversity of functional groups attached to the nitrogen center (N–R). The origin of the high SIV-selectivity is elucidated by density functional theory calculations, suggesting a stepwise mechanism for the aryne substrates and a concerted mechanism for the cyclic alkynes. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The rapid synthesis of structurally complicated electron donors & acceptors still remains a major challenge in organic solar cells (OSC). In this work, we developed a highly efficient strategy to access long‐chain oligomeric donor and acceptors for OSC applications. A series of cyclopentadithiophene (CPDT) and benzothiadiazole (BT)‐based π‐conjugated oligomers, i.e., three oligomeric acceptors (BTDT)n‐IC (n = 1—3) and one long‐chain oligomeric donor (BTDT)4‐RD, are facilely synthesized by an atom‐ and step‐economical, and labor‐saving direct C—H arylation (DACH) reaction (i.e., C—H/C—Br cross coupling). Note that (BTDT)4‐RD involving five CPDT, four BT and two rhodamine (RD) building blocks is the longest oligomeric donor in the fullerene‐free OSC devices ever reported. The dependence of the structure‐property‐performance correlation of (BTDT)n‐IC (n = 1—3) and (BTDT)4‐RD on the π‐conjugation lengths is thoroughly investigated by opto‐electrochemical measurements, bulk heterojunction (BHJ) OSC devices and microscopies. The (BTDT)1‐IC:PBDB‐T and (BTDT)4‐RD:Y6 BHJs achieve power conversion efficiencies of 9.14% and 4.51%, respectively. Our findings demonstrate that DACH reaction is a powerful tool to tune the opto‐electronic properties and device performances by regulating the lengths of π‐conjugated oligomers with varied numbers of repeating units. [ABSTRACT FROM AUTHOR]

A series of asymmetric pyridine‐bridged imidazole‐pyridine‐amino acid ligands was successfully synthesized and characterized by HR‐MS, 1H, 13C NMR spectroscopy. These ligands assisted palladium catalyzed C−H bond activation of imidazoles at the C5 position with aryl chlorides and aryl bromides without pivalic acid conditions. Various of less reactive aryl chlorides were allowed to prepare arylated heterocycles. The mechanism study indicated the structure role for amino acid and imidazole. [ABSTRACT FROM AUTHOR]

Bicyclo[1.1.1]pentane (BCP) derivatives have attracted significant recent interest in drug discovery as alkyne, tert‐butyl and arene bioisosteres, where their incorporation is frequently associated with increased compound solubility and metabolic stability. While strategies for functionalisation of the bridgehead (1,3) positions are extensively developed, platforms allowing divergent substitution at the bridge (2,4,5) positions remain limited. Recent reports have introduced 1‐electron strategies for arylation and incorporation of a small range of other substituents, but are limited in terms of scope, yields or practical complexity. Herein, we show the synthesis of diverse 1,2,3‐trifunctionalised BCPs through lithium‐halogen exchange of a readily accessible BCP bromide. When coupled with medicinally relevant product derivatisations, our developed 2‐electron "late stage" approach provides rapid and straightforward access to unprecedented BCP structural diversity (>20 hitherto‐unknown motifs reported). Additionally, we describe a method for the synthesis of enantioenriched "chiral‐at‐BCP" bicyclo[1.1.1]pentanes through a novel stereoselective bridgehead desymmetrisation. [ABSTRACT FROM AUTHOR]

We report herein an unprecedented hypervalent iodine(III)‐catalysis using the activated sulfoxide. Since the present catalytic systems promote the dehydrogenative cycloisomerization‐arylation reaction of 2‐propargyl 1,3‐dicarbonyl compounds with aromatics, this report also provides one of the few methods for iodine(III)‐catalyzed intermolecular carbon‐carbon bond formation of aromatics. [ABSTRACT FROM AUTHOR]

Modular and regio-/stereoselective syntheses of all-carbon tetrasubstituted olefins from simple alkene materials remain a challenging project. Here, we demonstrate that a remote-carbonyl-directed palladium-catalyzed Heck/isomerization/C(sp2)–H arylation sequence enables unactivated 1,1-disubstituted alkenes to undergo stereoselective terminal diarylation with aryl iodides, thus offering a concise approach to construct stereodefined tetrasubstituted olefins in generally good yields under mild conditions; diverse carbonyl groups are allowed to act as directing groups, and various aryl groups can be introduced at the desired position simply by changing aryl iodides. The stereocontrol of the protocol stems from the compatibility between the E/Z isomerization and the alkenyl C(sp2)–H arylation, where the vicinal group-directed C(sp2)–H arylation of the Z-type intermediate product thermodynamically drives the reversible E to Z isomerization. Besides, the carbonyl group not only promotes the Pd-catalyzed sequential transformations of unactivated alkenes by weak coordination, but also avoids byproducts caused by other possible β-H elimination. The synthesis of highly substituted olefins has been pursued for decades. Here, the authors show a carbonyl-directed sequential Heck/isomerization/C–H arylation of alkenes for modular synthesis of stereodefined all-carbon tetrasubstituted olefins. [ABSTRACT FROM AUTHOR]

Atropisomeric phosphines hold considerable significance in asymmetric catalysis, yet their synthesis presents a formidable challenge owing to intricate multistep procedures. In this context, a groundbreaking methodology has been presented for their preparation. This innovative approach entails an atroposelective rhodium‐catalyzed C−H activation employing aryl and heteroaryl halides, chelated by a P(III) center. The essence of this strategy lies in its ability to directly construct chiral phosphine ligands in a single step, thereby exhibiting exceptional efficiency in terms of atom and redox economy. Illustrative examples serve to demonstrate the immense potential of in situ‐formed ligands in asymmetric catalysis. Mechanistic experiments have further provided invaluable insights into this transformation. [ABSTRACT FROM AUTHOR]

An arylation protocol for pyridines is described, via the ring‐opened Zincke intermediate. Treatment of pyridines with triflic anhydride and a secondary amine produces an azahexatriene species, which undergoes regioselective Pd‐catalyzed arylation at the putative C4 position. Recyclization then provides the pyridine products. Alternatively, metal‐free arylation with a diaryliodonium salt is selective for the pyridine meta‐position, affording a regiodivergent approach to pyridine biaryls from a common intermediate. [ABSTRACT FROM AUTHOR]

There is a pressing need, particularly in the field of drug discovery, for general methods that will enable direct coupling of tertiary alkyl fragments to (hetero)aryl halides. Herein a uniquely powerful and simple set of conditions for achieving this transformation with unparalleled generality and chemoselectivity is disclosed. This new protocol is placed in context with other recently reported methods, applied to simplify the routes of known bioactive building blocks molecules, and scaled up in both batch and flow. The role of pyridine additive as well as the mechanism of this reaction are interrogated through Cyclic Voltammetry studies, titration experiments, control reactions with Ni(0) and Ni(II)‐complexes, and ligand optimization data. Those studies indicate that the formation of a BINAPNi(0) is minimized and the formation of an active pyridine‐stabilized Ni(I) species is sustained during the reaction. Our preliminary mechanistic studies ruled out the involvement of Ni(0) species in this electrochemical cross‐coupling, which is mediated by Ni(I) species via a Ni(I)‐Ni(II)‐Ni(III)‐Ni(I) catalytic cycle. [ABSTRACT FROM AUTHOR]

Rh‐catalyzed asymmetric C(sp3)−H arylation of 8‐benzylquinolines with arylboronic acids was developed. In the presence of 5 mol% BINOL‐derived chiral cyclopentadienyl rhodium complex, asymmetric benzylic C(sp3)−H bond arylation reaction proceeded smoothly to afford a series of enantioenriched triarylmethanes in moderate to good yields with good to excellent enantioselective control (24–89% yields, 63–93% ee). The method displays a broad substrate scope and good functional group tolerance under mild conditions. [ABSTRACT FROM AUTHOR]

Donor–acceptor (D–A) conjugated polymer (CP) featuring high charge mobility and widely tunable energy bands have shown promising prospects in photocatalysis. In this work, a library of ternary D‐A CPs (22 polymers) based on benzothiadiazole, bithiophene, and fluorene derivatives (i.e., fluorene [Fl], 9,9‐dihexylfluorene [HF], and 9,9′‐spirobifluorene [SF]) with and without alkyl side chains, and with 3D geometry are designed and synthesized via atom‐economical direct C–H arylation polymerization to explore the synergetic effects of stereochemistry, D/A ratio, and alkyl chains on the properties and photocatalytic performances, which reveal that 1) the cross‐shaped 3D spirobifluorene (SF) building block shows the highest hydrogen evolution rates (HER) owing to the sufficient photocatalytic active sites exposed, 2) the alkyl‐free linear polymer (FlBtBT0.05) exhibit the highest photocatalytic pollutant degradation performance owing to its superior charge separation, and 3) the alkyl side chains are redundances that will exert detrimental effects on the aqueous photocatalysis owing to their insulating and hydrophobic property. The structure‐property‐performance correlation results obtained will provide a desirable guideline for the rational design of CP‐based photocatalysts. [ABSTRACT FROM AUTHOR]

This article provides an overview of the recent progress and prospects of using palladium nanoparticles (Pd NPs) as catalysts for the synthesis of functionalized heterocycles through C(sp2)-H arylation. Heterocycles are important in various fields, including pharmaceuticals and materials science. Traditional synthetic approaches have limitations, but transition-metal-catalyzed C-H activation offers a more efficient alternative. Heterogeneous catalytic approaches using Pd NPs show promise in terms of catalyst recoverability and reusability. The article discusses different methods and catalysts for the synthesis of functionalized heterocycles, highlighting their advantages and potential applications. [Extracted from the article]

Several N‐ethoxycarbonylmethyl enaminones, prepared by Eschenmoser sulfide contraction between N‐(ethoxycarbonylmethyl)pyrrolidine‐2‐thione and various ortho‐oxygenated phenacyl halides, underwent cyclisation to give ethyl 6‐aryl‐2,3‐dihydro‐1H‐pyrrolizine‐5‐carboxylates upon microwave heating with silica gel in xylene. With enaminones made from ortho‐hydroxyphenacyl halides, not only did dihydropyrrolizine formation take place, but spontaneous lactonisation also occurred to give 9,10‐dihydrochromeno[4,3‐b]pyrrolizin‐6(8H)‐ones. Bromination and Suzuki‐Miyaura arylation of these chromenopyrrolizines at the free C−H site on the pyrrole ring afforded four analogues of the lamellarin alkaloids in which a pyrrolidine ring replaces the isoquinoline system in the fused polycyclic core. The product 11‐(3,4‐dimethoxyphenyl)‐2,3‐dimethoxy‐9,10‐dihydrochromeno[4,3‐b]pyrrolizin‐6(8H)‐one, in particular, is a congener of the well‐known lamellarin G trimethyl ether. Preliminary results pertaining to an extension to chromenone‐fused indolizines are also reported. [ABSTRACT FROM AUTHOR]

The C−H bond functionalization of pyridyl C3‐position of 4‐arylpyridines using Pd 1,4‐migration has been investigated. Under suitable reaction conditions, oxidative addition of 4‐(2‐bromoaryl)pyridines to palladium followed by a Pd 1,4‐migration activates these pyridyl C3‐positions. Next, the Pd‐catalyzed coupling via C−H bond activation of the heteroarenes affords the C3‐heteroarylated 4‐arylpyridines. The new C−C bond created in this coupling reaction results from the functionalization of two C−H bonds. For this coupling reaction, a bromo‐substituent on the aryl unit of 4‐arylpyridines was employed as a traceless directing group. This heteroarylation method tolerates a range of substituents on the benzene ring as well as several heteroarenes. Moreover, from 3‐arylpyridines, C2‐ or C4‐functionalization of the pyridine ring also proved possible. In addition, this procedure uses an air‐stable catalyst and an inexpensive base. [ABSTRACT FROM AUTHOR]

CH-arylated quinolines have found widespread applications in drug discovery as well as in the field of fine chemicals and material science. Herein, we report a general, transition-metal-free, environmentally friendly photocatalytic strategy for the direct C–H arylation of quinolines and quinoline N-oxides/pyridines selectively at the C-8 and C-2 positions, respectively, using chlorophyll as the organic photocatalyst. This method offers a simple, practical route for direct access to C8-aryl quinolines, C2-aryl pyridines, and quinoline N-oxides. The key advantages of the present protocol include operational simplicity, the use of clean energy sources, low reagent costs, and no requirement of pre-functionalized substrates. [ABSTRACT FROM AUTHOR]

The cyclization of 5,6-diarylpyrrolo[3,4-d]pyrimidine-2,4-diones containing a halogen atom in the ortho-position of one of the aryl rings, proceeding as intramolecular C–H arylation catalyzed by Ru(II) complexes, was studied. It was found that complexes Ru(NHC)(cymene)Cl2, where NHC = IPr [1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene], IMes [1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene], and their derivatives containing substituents at positions 4 and 5 of the imidazole ring, exhibit high catalytic activity. Based on the reaction studied, new representatives of pyrimido[5',4':3,4]pyrrolo[1,2-f]phenanthridine were obtained. [ABSTRACT FROM AUTHOR]

During the last few years, research on new approaches for the synthesis of diaryl selenides containing heterocyclic compounds (Heterocyclic-Selenide-Aryl derivatives) has gained special importance among chemists. These compounds are very valuable from pharmaceutical and pharmacological points of view, and several biological properties such as anti-cancer and antitumor properties have been reported about them. In this research, we presented an ecofriendly and efficient method to prepare diaryl selenides containing heterocyclic compounds through one-pot three-component reactions of heterocyclic compounds with aryl iodides and selenium catalyzed by Fe3O4@DABA-PQ-CuCl2 nanocomposite in PEG as solvent under thermal conditions. Fe3O4@DABA-PQ-CuCl2 nanocomposite was successfully fabricated by using simple method and was fully identified by several spectroscopic techniques. The use of nanocatalysts synthesized in this work has the following advantages over the catalysts reported in the articles: low toxicity, easy storage, transportation, weighing and application, easy preparation of catalyst from cheap and available raw materials, high activity of catalyst due to increased surface area, stability in solvents and at high temperatures, high selectivity, recyclability and reuse of catalyst. [ABSTRACT FROM AUTHOR]

A domino SNAr‐ihDA/rDA reaction was developed from rarely exploited 3‐fluoro‐1,2,4‐triazines with bifunctional alkyne tethered nucleophiles to construct various fused non‐aromatic/heteroaromatic bicycles in yields ranging from 56 to 99%, notably within the family of valuable spirooxindole derivatives. In this study, the challenging enantioselective phase‐transfer catalyzed arylation of a sulfonyl‐triazine was also demonstrated with up to 66% ee. In both racemic and asymmetric processes, the nature of the leaving group at C3 was key to successfully achieve these sequences. [ABSTRACT FROM AUTHOR]

This work discloses an iridium-catalyzed selective arylation of B(6)–H of 3-Ar-o-carboranes with arylboronic acid via direct B–H activation for the first time. A series of unsymmetric and symmetric 3,6-diaryl-o-carboranes decorated with diverse active groups have been synthesized with moderate to excellent yields under mild conditions. This work offers an efficient approach for selective arylation of B(6)–H with arylboronic acid and has important value for selective functionalization of o-carboranes. [ABSTRACT FROM AUTHOR]

Site‐selective functionalization strategies are in high demand to prepare well‐defined homogeneous proteins for basic research and biomedical applications. In this regard, cysteine‐based reactions have enabled a broad set of transformations to produce modified proteins for various applications. However, these approaches were mainly employed to modify a single reactive site with a specific transformation. Achieving site selectivity or multiple transformations, essential for preparing complex biomolecules, remains challenging. Herein we demonstrate the power of combining palladium(II)‐mediated C−S bond formation and C−S bond cleavage reactions to selectively edit desired cysteine sites in complex and uniquely modified proteins. We developed an orthogonal palladium(II) strategy for rapid and effective diversification of multiple cysteine sites (3–6 residues) with various transformations. Importantly, we employed our approach to prepare 10 complex analogues, including modified, stapled, and multimeric proteins on a milligram scale. Furthermore, we also synthesized a focused library of stabilized artificial transcription factors that displayed enhanced stability and potent DNA binding activity. Our approach enables rapid and effective protein editing and opens new avenues to engineer new biomolecules for fundamental research and therapeutic applications. [ABSTRACT FROM AUTHOR]

Aromatic amines are ubiquitous moieties in organic molecules and their direct functionalization is of great interest in many research areas due to their prevalence in pharmaceuticals and organic electronics. While several synthetic tools exist for the ortho‐ and para‐functionalization of anilines, the functionalization of the less reactive meta‐position is not easy to achieve with current methods. To date, the meta‐C−H arylation of aniline derivatives has been restricted to either the use of directing groups & templates, or their transformation into anilides & quaternary anilinium salts. Herein, we report the first general and efficient meta‐C−H‐arylation of non‐directed aniline derivatives via cooperative catalysis with a palladium–S,O‐ligand–norbornene system. The reaction proceeds under mild conditions with a wide range of aniline derivatives and aryl iodides, while being operationally simple and scalable. Our preliminary mechanistic investigation–including the isolation of several palladium complexes and deuterium experiments–reveal useful insights into the substituent‐effects of both the aniline‐substrate and the norbornene‐mediator during the meta‐C−H activation step. [ABSTRACT FROM AUTHOR]