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Comprehensive Summary: Organoborons are commonly used building blocks for rapidly increasing molecular complexity. Although significant progress has been made in the selective functionalization of mono‐organoborons, the site‐selective functionalization of poly(organoborons) has attracted substantial interest in organic synthesis, pharmaceuticals, and agrochemicals due to the presence of multiple potential reaction sites. This review discusses various activation modes of the target C–B bond, with diverse transformations being achieved in both a selective and efficient manner. Recent advances in the catalytic selective transformations of 1,n‐diboronates through ionic and radical pathways are highlighted. Furthermore, we summarize the existing challenges and future research directions in this field. Key Scientists: In 1993, Suzuki, Miyaura and coworkers developed a pioneering example of selective arylation towards cis‐1,2‐bis(boryl) alkenes, marking the inception of this field. The Morken group has made significant contributions to the asymmetric diboration of alkenes and realized elegant catalytic functionalization of these compounds since 2004. In 2016, Fernández and colleagues achieved the selective arylation of the internal C–B bond of tri(boronates). Since 2019, the Aggarwal group has developed efficient Giese‐type addition and selective arylation at the more substituted C–B bond of 1,2‐bis(boronic) esters through photoredox catalysis. The controllable regiodivergent alkynylation of 1,3‐bis(boronic) esters was developed by Gao and coworkers in 2023. Recently, Qin conducted elegant research on the programmable late‐stage functionalization of bridge‐substituted bicyclo[1.1.1]pentane (BCP) bis‐boronates. Since 2013, catalytic stereoselective transformations have been developed by several groups, including those led by Morken and Chen. This review summarizes the latest and most significant developments in this field since 1993. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Organoborons are commonly used building blocks for rapidly increasing molecular complexity. Although significant progress has been made in the selective functionalization of mono‐organoborons, the site‐selective functionalization of poly(organoborons) has attracted substantial interest in organic synthesis, pharmaceuticals, and agrochemicals due to the presence of multiple potential reaction sites. This review discusses various activation modes of the target C–B bond, with diverse transformations being achieved in both a selective and efficient manner. Recent advances in the catalytic selective transformations of 1,n‐diboronates through ionic and radical pathways are highlighted. Furthermore, we summarize the existing challenges and future research directions in this field. Key Scientists: In 1993, Suzuki, Miyaura and coworkers developed a pioneering example of selective arylation towards cis‐1,2‐bis(boryl) alkenes, marking the inception of this field. The Morken group has made significant contributions to the asymmetric diboration of alkenes and realized elegant catalytic functionalization of these compounds since 2004. In 2016, Fernández and colleagues achieved the selective arylation of the internal C–B bond of tri(boronates). Since 2019, the Aggarwal group has developed efficient Giese‐type addition and selective arylation at the more substituted C–B bond of 1,2‐bis(boronic) esters through photoredox catalysis. The controllable regiodivergent alkynylation of 1,3‐bis(boronic) esters was developed by Gao and coworkers in 2023. Recently, Qin conducted elegant research on the programmable late‐stage functionalization of bridge‐substituted bicyclo[1.1.1]pentane (BCP) bis‐boronates. Since 2013, catalytic stereoselective transformations have been developed by several groups, including those led by Morken and Chen. This review summarizes the latest and most significant developments in this field since 1993. [ABSTRACT FROM AUTHOR]

An efficient heterogeneous Pd/Cu synergistic catalysis system without a ligand was utilized for C–H arylation of azoles. The reaction exhibits excellent catalytic activity with high functional group tolerance. The synergistic effect between the Cu2O core and PdCu shell was confirmed, whereas pure PdCu nanocages and Cu2O exhibited negligible catalytic activity. [ABSTRACT FROM AUTHOR]

A simple, direct, and regioselective protocol to substituted 5-iodo-4 H -quinoxalines through double C–N arylations of 1,2,3-triiodobenzenes and 1,2-diamines is reported. Remarkably, the N-arylation couplings proceed unimolecularly at the vicinal positions, the most active and less hindered positions. This process tolerates a wide range of aromatic substrates. The reactions of electron-deficient 1,2,3-triiodoarene systems and DMEDA under the optimized conditions provided the highest isolated yields. The chemical transformation of the target compound, which serves as a valuable precursor in synthesis, was successfully demonstrated in the Suzuki–Miyaura reaction, giving the desired coupling derivatives with excellent isolated yields. This article describes a method for the first and unprecedented synthesis of 5-iodo-4 H -quinoxalines that is regioselective, scalable, and provides useful derivatives for other chemical reactions [ABSTRACT FROM AUTHOR]

Herein we report synthesis of pyrene-azobenzene dyads using the Pd(II)-catalyzed directing-group-assisted arylation of the ortho C(sp2)–H bond of pyrenecarboxamides as a key transformation. Many examples of directly connected pyrene-azobenzene dyads (without any linker) and glycine-based azobenzene-pyrene dyads have been synthesized. Initial incorporation of an acetanilide unit in the pyrene skeleton through Pd(II)-catalyzed directing-group-assisted ortho C(sp2)–H arylation by using iodoacetanilide was followed by the transformation of the acetanilide into an azobenzene unit to give the pyrene-azobenzene dyad. UV-Vis spectroscopic studies were performed to get the absorption properties (λmax (nm)) of all the compounds. Preliminary photoswitching studies in both forward and reverse directions and their related thermal reverse Z → E isomerization kinetics measurements were ascertained for representative compounds. Considering the importance of pyrene and azobenzene linked motifs as important chromophore-based photoswitchable molecules in chemical, materials, and supramolecular sciences research fields, this work enriches the library of pyrene-azobenzene dyads. [ABSTRACT FROM AUTHOR]

4‐Aryl‐1,4‐dihydropyridines are prevalent pharmacophores and versatile building blocks in medicinal and synthetic chemistry. Herein, we demonstrated a mechanistically distinct radical‐radical cross‐coupling approach to 4‐aryl‐1,4‐dihydropyridines, via direct C4−H arylation of 1,4‐dihydropyridines with readily available cyanoarenes. This mild protocol is initiated by the direct photoexcitation of 1,4‐dihydropyridines, eliminating the need for expensive photocatalysts and enabling operation under ambient air conditions. [ABSTRACT FROM AUTHOR]

Alkenes are ubiquitous in natural and synthetic molecules and constitute versatile building blocks. Remarkably, their radical 1,2‐difunctionalization offers a valuable synthetic tool for rapidly accessing multifunctional compounds through a step and atom‐ economy process. More particularly, the addition of (hetero)aromatic groups onto alkenes is of particular appeal given the numerous applications of aromatic compounds in various fields. However, such process becomes difficult when attempted on simple non‐conjugated aliphatic alkenes (unactivated alkenes). In this context, the (hetero)arylation of unactivated alkenes through the radical functionalization followed by remote (hetero)aryl migration has recently emerged as a powerful opportunity to address the lack of reactivity of such π systems. The advances in radical chemistry have led to a flood of synthetic methods to trigger the addition of a carbon‐ or heteroatom‐centered radical/(hetero)aryl migration sequence. Interestingly, the migration of the aromatic ring can take place from various atoms. This feature has spurred the design of several substrates allowing such a process to occur. This review intends to provide an overview of the contributions according to the type of substrates that have been employed. The reaction scope, limitations and mechanistic aspect will be discussed with the aim of stimulating efforts in this research area. [ABSTRACT FROM AUTHOR]

Given the pivotal role of β‐(het)arylethylamine moiety in bioactive molecules, the direct amino(het)arylation of alkenes occupies a privileged position in the construction of (het)arylethylamine derivatives. Herein we devise chiral sulfoximines as novel bifunctional reagents which exhibit remarkable efficiency in the challenging asymmetric alkene aminohetarylation reaction, particularly in terms of reactivity and stereo‐control. The chiral reagents can be conveniently accessed in gram scale, and efficiently generate N‐centered radicals under mild photochemical conditions. The transformation proceeds through enantioselective 1,4‐hetaryl migration, ensuring precise chirality transfer from sulfur‐ to carbon‐centers, rendering wide applicability to both aromatic and aliphatic alkenes. Furthermore, the method is straightforward to operate and does not require transition metals or photosensitizers, making it an attractive and practical option. [ABSTRACT FROM AUTHOR]

Herein we developed a palladium-catalyzed coupling of 2,3-enopyranose with arylboronic acid using a removable oxyacetamide directing group, which provides an efficient method for the synthesis of C-2 aryl sugars. The synthesized products were subsequently utilized as glycosyl donors in O/S glycosylation, enabling regio- and stereoselective production of 1,2-disubstituted branched sugars. [ABSTRACT FROM AUTHOR]

Unlike traditional multi‐step synthetic approaches, we developed a single‐step synthesis of versatile π‐conjugated building blocks bearing post‐functionalizable C−H and C−Br bonds. Direct C−H arylation of 3‐bromothiophene with various iodo(hetero)aryls was successfully carried out with good regio‐ and chemo‐selectivity. Under optimized reaction conditions, 20 new compounds were facilely prepared in yields up to 91 %. One of the obtained compounds was demonstrated to further extend its conjugation length using a succinct synthetic plan to create two symmetrical oligo(hetero)aryls (MLC01 and MLC02) that were fabricated as effective hole‐transporting materials (HTM) for perovskite solar cells (PSC). PSC devices utilizing MLC01 as hole‐transport layer displayed promising power conversion efficiencies of up to 17.01 %. [ABSTRACT FROM AUTHOR]

We report a method to furnish substituted 1H‐indazoles via a coupling of 3‐acetyl substituted nitroarenes and arylhydrazines. Reactions progressed in the presence of cobalt(II) acetylacetonate catalyst, TEMPO oxidant, and Cs2CO3 base. Functional groups including bromo, chloro, nitro, and trifluoromethoxy groups were compatible with reaction conditions. The proposed mechanism was based on a nucleophilic substitution of hydrogen para to nitro group. Our method feature a convenient pathway to directly obtain substituted 1H‐indazoles which avoid the use of pre‐functionalized starting materials. Indazole could play a role as the directing group for a palladium‐catalyzed C(sp2)─H arylation with iodobenzene. [ABSTRACT FROM AUTHOR]

The synthesis of biaryl amides, which are prevalent motifs in bioactive molecules, often necessitates lengthy and inefficient procedures. To address these limitations, catalytic C−H activation protocols have emerged, enabling the direct ortho‐arylation of aryl amides. However, these protocols often suffer from issues such as lack of selectivity, reliance on stoichiometric oxidants, and the requirement for excess reagents and harsh reaction conditions. To overcome these challenges, we present a novel and highly selective protocol for the ortho‐arylation of N‐aryl amides and ureas. The high selectivity originates from the directed installation of BBr3 to form a boracycle, which then undergoes cross‐coupling with an aryl halide. Our method offers significant advantages, including mild reaction conditions, excellent site‐specificity, and scalability. The protocol demonstrates broad compatibility with a diverse range of readily accessible functionalized anilides and aryl iodides, as evidenced by 55 successful examples yielding products in the 30–95 % range. Furthermore, our methodology surpasses conventional approaches by facilitating the one‐pot selective diagonal diarylation of dianilides. This capability unlocks the construction of previously unattainable diagonal aryl systems, which serve as valuable precursors for the synthesis of diagonal tetraarylbenzenediamines and N‐doped fulminenes, two crucial compound classes in materials science. [ABSTRACT FROM AUTHOR]

ABSTRACT A simple, direct, and regioselective protocol to the synthesis of N1,N2‐bis(2,3‐diiodoaryl)benzene‐1,2‐diamines through highly regioselective microwave‐assisted/palladium‐catalyzed double C‐N arylations of 1,2,3‐triiodobenzene and benzene‐1,2‐diamine is reported. Remarkably, the C‐N arylations proceeded bimolecularly at the terminal positions, the most active and less hindered position. This process was efficient and tolerated a wide range of substrates. The reaction of electron‐rich/neutral 1,2,3‐triiodoarene systems and electron‐rich 1,2‐diamines under the optimized conditions provided the highest isolated yields. This article describes a method for the first and unprecedented synthesis of tetra‐iodinated N1,N2‐diarylbenzene‐1,2‐diamine and iodinated 5,10‐dihydrophenazine products that is regioselective and scalable and provides useful derivatives for other chemical reactions especially in the synthesis of new NHC ligands. [ABSTRACT FROM AUTHOR]

BODIPYs have a well‐established role in biological sciences as chemosensors and versatile biological markers due to their chemical reactivity, which allows for fine‐tuning of their photophysical characteristics. In this work, we combined the unique reactivity of arylazo sulfones with the advantages of a "sunflow" reactor to develop a fast, efficient, and versatile method for the photochemical arylation of BODIPYs and other chromophores. This approach resulted in red‐shifted emitting fluorophores due to extended electronic delocalization at the 3‐ and 5‐positions of the BODIPY core. This method represents an advantageous approach for BODIPY functionalization compared to existing strategies. [ABSTRACT FROM AUTHOR]

The development of simplified synthetic strategy to create structurally and functionally diverse pseudo‐natural macrocyclic molecules is highly appealing but poses a marked challenge. Inspired by natural scaffolds, herein, we describe a practical and concise ligand‐enabled Pd(II)‐catalyzed sp3 C−H alkylation, olefination and arylation macrocyclization, which could offer a novel set of pseudo‐natural macrocyclic sulfonamides. Interestingly, the potential of ligand acceleration in C−H activation is also demonstrated by an unprecedented enantioselective sp3 C−H alkylation macrocyclization. Moreover, a combination of in silico screening and biological evaluation led to the identification of a novel spiro‐grafted macrocyclic sulfonamide 2 a, which showed a promising efficacy for the treatment of Parkinson's disease (PD) in a mouse model through the activation of silent information regulator sirtuin 3 (SIRT3). [ABSTRACT FROM AUTHOR]

A selective direct arylation of the different Csp2‐H bonds of imidazo[2,1‐b]thiazole with (hetero) aryl halides can be achieved simply by switching from a palladium catalyst system to the use of stoichiometric amounts of copper. The observed selectivity, also rationalized by DFT calculations, can be explained by a change in the mechanistic pathways between electrophilic palladation and base‐promoted C−H metalation. [ABSTRACT FROM AUTHOR]

We report a green and efficient visible-light-driven method for the arylation and alkylation of quinoxalin-2(1H)-ones and quinolines. This catalyst-free process utilizes air as the oxidant, offering mild reaction conditions, environmental sustainability, and broad functional group compatibility. The approach enables the synthesis of aryl and alkyl derivatives of quinoxalin-2(1H)-ones and quinolines with high to excellent yields. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: We herein describe a Cp*RhIII‐catalyzed C(sp3)–H mono‐arylation of 8‐methylquinolines with benign arylsilanes. The use of 1‐adamantane carboxylic acid can benefit the efficiency in this transformation, and AgF was both activator and reoxidant. Control experiments indicated inability of C—H cleavage in determining the rate of the reaction. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Concise assembly of spirooxindoles is of great significance but a challenging task in modern organic synthesis. Described herein is an unusual base‐promoted [4+2] spiroannulation of rarely used isatin‐derived β‐silylcarbinols with o‐halogen aromatic ketones, which enables rapid and modular synthesis of six‐membered carbocyclic spirooxindoles in high yields with excellent functional group tolerance (> 50 examples). Mechanistic experiments revealed that this reaction involved a Peterson olefination, Michael addition and intramolecular C(sp3) arylation cascade. The variegated synthetic derivatization of target products and successful construction of bioactive molecules further illustrate the synthetic potential in spirooxindole‐related drug discovery. [ABSTRACT FROM AUTHOR]

The catalytic asymmetric dearomative arylation of 2‐naphthols enabled by the unconventional reactivity of o‐quinone diimides, i. e. the 1,4‐conjugate addition on quinone sp2 hybridized carbon, has been established. Under the catalysis of chiral phosphoric acid, various cyclohexaenones bearing an all‐carbon quaternary stereocenter have been prepared with excellent yields and enantioselectivities. [ABSTRACT FROM AUTHOR]

Transition metal-catalyzed addition of organometallics to aryl(alkyl)alkynes has been well known to proceed with the regioselectivity in forming a carbon–carbon bond at the alkyl-substituted carbon (β-addition). Herein, the reverse regiochemistry with high selectivity in giving 1,1-diarylalkenes (α-addition) was realized in the reaction of arylboronic acids with aryl(alkyl)alkynes by use of a rhodium catalyst coordinated with a chiral diene ligand, whereas the arylation of the same alkynes proceeded with the usual regioselectivity (β-addition) in the presence of a rhodium/DM-BINAP catalyst. The regioselectivity can be switched by the choice of ligands on the rhodium catalysts. This reverse regioselectivity also enabled the catalytic asymmetric synthesis of phoenix-like axially chiral alkylidene dihydroanthracenes with high enantioselectivity through an α-addition/1,4-migration/cyclization sequence. Transition-metal-catalysed additions of carbon species to aryl(alkyl)alkynes is an established and useful methodology for building towards useful molecular complexity. Here, the authors present rhodium-catalysed regiodivergent additions to aryl(alkyl)alkynes, which allows access to the uncommonly found α-addition products through modulation of the ligand choice. [ABSTRACT FROM AUTHOR]

Direct functionalization of C−H bonds is the most expeditious strategy to build complexity into organic molecules. Unfortunately, most Pd‐catalyzed C−H arylation strategies require high temperatures and/or stoichiometric oxidants. The discovery of metallaphotoredox C−H arylation in 2011 forged a new approach to achieve metal catalyzed C−H arylation at room temperature. Since this discovery, most reports still use explosive diazonium salts as aryl radical precursors. Alternatively, a single report uses bench‐stable diaryliodonium salts, albeit with an Ir‐based photocatalyst. In this study, we develop an organophotoredox manifold that enables Pd‐catalyzed C−H arylation of numerous N‐aryl amide substrates. The results we present are expected to revitalize the use of diaryliodonium salts to achieve room temperature arylations of wide‐ranging classes of C−H bonds. [ABSTRACT FROM AUTHOR]

Isomerisation reactions provide streamlined routes to organic compounds which are otherwise hard to directly synthesise. The most common forms are positional, geometrical or stereochemical isomerisations which involve the relocation of a double bond or a change in relative location of groups in space. In contrast, far fewer examples of structural (or constitutional) isomerisation exist where the connectivity between atoms is altered. The development of platforms capable of such rearrangement poses a unique set of challenges because chemical bonds must be selectively cleaved, and new ones formed without overall addition or removal of atoms. Here, we show that a dual catalytic system can enable the structural isomerisation of readily available allylic alcohols into more challenging‐to‐synthesise α‐arylated ketones via a H‐atom transfer initiated semi‐pinacol rearrangement. Key to our strategy is the combination of a cobalt catalyst and photocatalyst under reductive, protic conditions which allows intermediates to propagate catalytic turnover. By providing an unusual disconnection to structural motifs which are difficult to access through direct arylation, we anticipate inspiring other advanced catalytic isomerisation strategies that will further retrosynthetic logic for complex molecule synthesis. [ABSTRACT FROM AUTHOR]

We developed a redox-neutral synthesis of isoindoloindolone via intramolecular arylation of 2-(1 H -indole-1-carbonyl)benzoic acids. This protocol facilitates the formation of various substituted isoindoloindolones in yields ranging from 17% to 80%. Our mechanistic investigations indicate the pivotal role of NaI: the iodide anion promotes the formation of the desired isoindoloindolone, and the sodium cation suppresses the formation of acylated byproducts, thereby enabling the selective formation of isoindoloindolones in acceptable yields. [ABSTRACT FROM AUTHOR]

Radical‐involved arylative cross‐coupling reactions have recently emerged as an attractive strategy to access valuable aryl‐substituted motifs. However, there still exist several challenges such as limited scope of radical precursors/acceptors, and lack of general asymmetric catalytic systems, especially regarding the multicomponent variants. Herein, we reported a general copper‐Box system for asymmetric three‐component arylative radical cross‐coupling of vinylarenes and 1,3‐enynes, with oxime carbonates and aryl boronic acids. The reactions proceed under practical conditions in the absence or presence of visible‐light irradiation, affording chiral 1,1‐diarylalkanes, benzylic alkynes and allenes with good enantioselectivities. Mechanistic studies imply that the copper/Box complexes play a dual role in both radical generation and ensuing asymmetric cross‐coupling. In the cases of 1,3‐enynes, visible‐light irradiation could improve the activity of copper/Box complex toward the initial radical generation, enabling better efficiency match between radical formation and cross‐coupling. [ABSTRACT FROM AUTHOR]

We report a dual transition metal electrocatalytic approach for C(sp3)–C(sp3) bond cleavage and arylation of cyclic alcohols, providing an efficient and sustainable method for site-specific arylation of ketones. The reaction involves electrophotochemical cerium-catalysed generation of alkoxyl radicals from readily accessible alcohols. Subsequently, homolytic cleavage of the β-C–C bond leads to the generation of carbon-centered radicals that could be effectively utilized by nickel catalysis powered by cathode reduction to deliver the remote arylated ketone products. [ABSTRACT FROM AUTHOR]

We present an improved and convenient synthesis of [2.2]paracyclophane‐imidazoline N,O‐ligands with central and planar chirality in seven steps starting from [2.2]paracyclophane. The utility of these ligands in organozinc additions to aldehydes is described. The asymmetric ethylation of aldehydes proceeded with enantioselectivities of up to 97 % ee, while the asymmetric arylation of aldehydes gave up to 95 % ee (R) and 82 % ee (S) using (S,S,SP)‐UCD‐Imphanol and (S,S,RP)‐UCD‐Imphanol, respectively. [ABSTRACT FROM AUTHOR]

An enantioselective arylation of isoxazoles with N‐Cbz‐protected azonaphthalenes is disclosed, affording a range of axially chiral arylisoxazoles in good yields and excellent enantiocontrol by utilizing chiral phosphoric acid. Cbz protecting group can be readily removed, resulting in five‐six membered axially chiral heterobiaryl amines bearing free amine maintaining enantiomeric purity. [ABSTRACT FROM AUTHOR]

We report the development of a novel synthetic approach for the highly strained atrop‐Tyr C‐6‐to‐Trp N‐1′ linkage, which can be executed on a decagram scale using a modular strategy involving palladium‐catalyzed C−H arylation followed by Larock macrocyclization. The first total synthesis of lapparbin (1) was achieved by applying this synthetic strategy. Furthermore, the modular synthesis utilizing C−H arylation and Larock macrocyclization, discovered in the total synthesis of lapparbin (1), was demonstrated to be applicable to various arbitrary biaryl linkages, including non‐natural types. [ABSTRACT FROM AUTHOR]

This report describes a dual catalytic approach for the versatile C−H arylation of arenes under photo‐excitation at room temperature. The cooperative catalysis utilizes iron oxide magnetic nanoparticles (which mostly contain Fe3O4 along with some γ‐Fe2O3) as the potential photocatalyst, which merges with the Pd‐catalyzed C−H activation cycle for the reductive generation of aryl radical from aryl diazonium salt, revealing its photocatalytic activities. The method is applicable to a wide range of aryl coupling partners and different directing groups, demonstrating excellent productivity, nice co‐operativity and recyclability. Adequate control experiments and mechanistic studies assisted in establishing the radical‐based reaction mechanism for the C−H arylation occurring in the heterogeneous phase. [ABSTRACT FROM AUTHOR]

In this work, we describe an efficient and modular method for enantiodivergent accessing P(V)‐stereogenic molecules by utilizing the catalytic atroposelective Catellani‐type C−H arylation/desymmetric intramolecular N‐arylation cascade reaction. The enantioselectivity of this protocol was proved to be tuned by the polarity of the solvent, thus providing a wide range of both chiral P(V)‐stereogenic enantiomers in moderate to good yields with good to excellent enantiomeric excesses. Noteworthy is that the strategy developed herein represents an unprecedented example of solvent‐dictated inversion of the enantioselectivity of P(V)‐stereogenic compounds. [ABSTRACT FROM AUTHOR]

A series of palladium‐N‐heterocyclic carbene complexes (2 a‐e) were synthesized from corresponding N‐heterocyclic carbene precursors (1 a‐e) in good yields. The structural analysis of all novel compounds was done by spectroscopic methods and elemental analysis was also performed to evaluate the purity of the complexes. Further confirmations of complexes 2 a‐d were provided by X‐ray crystallography technique. Under optimized reaction conditions, the catalytic activity of the palladium‐N‐heterocyclic carbene complexes was reviewed by direct arylation of furan‐2‐carboxaldehyde and 1‐methylpyrrole‐2‐carboxaldehyde with varied aryl halides. This arylation showed productive and selective reaction at the C5‐position of heteroaryl derivatives. [ABSTRACT FROM AUTHOR]

A library of neutral and cationic palladium complexes of cis‐chelating hetero‐dicarbene ligands have been prepared. These ligands contain two different NHC donors allowing for a wider degree of variation, and the impact of the distinct NHC units has been compared using various spectroscopic means. In addition, the catalytic activities of these complexes in the direct C‐H arylation of thiophenes with aryl halides were studied leading to the finding that the neutral dibromido complexes of the type [PdBr2(diNHC)] generally outperformed their cationic [Pd (NCMe)2(diNHC)](OTf)2 counterparts. More importantly, complexes containing more distinct NHC units give rise to superior catalysts due to an amplified "stereoelectronic asymmetry" within the complex. A preliminary photophysical study of some selected thiophene reaction products has been conducted as well. The ability to individually change each NHC donor in such dicarbene ligands allows for a better fine‐tuning of complex properties in search for superior catalysts. [ABSTRACT FROM AUTHOR]

Recently, PEPPSI‐type palladium‐complexes bearing N‐heterocyclic carbene (NHC) ligand have commonly been used as the effective catalysts in the direct arylation of heteroaromatic compounds. In most of previous studies catalyzed by such complexes, unsaturated ring carbene ligands such as benzo[d]imidazol‐2‐ylidene and imidazol‐2‐ylidene were used. However, the use of saturated ring carbene ligands such as 4,5‐dihydro‐imidazol‐2‐ylidene has been highly limited. Therefore, in this study, four novel 4,5‐dihydro‐1H‐imidazolium salts were synthesized as saturated ring carbene precursors. Then, well‐defined air‐ and moisture‐stable four novel PEPPSI‐type palladium‐complexes with 4,5‐dihydro‐imidazol‐2‐ylidene ligands were prepared. All synthesized carbene precursors and palladium‐complexes were structurally characterized by different spectroscopic and analytical techniques. Further structural characterization of two of the palladium‐complexes was performed by single‐crystal X‐ray diffraction. Next, the palladium‐complexes were tested in the direct arylation of azoles such as 4,5‐dimethylthiazole and 1‐methyl‐1H‐imidazole with (hetero)aryl halides in presence of 1 mol% catalyst loading at 120°C. The results showed that these novel palladium complexes are effective catalysts. [ABSTRACT FROM AUTHOR]

Pd(II)‐catalyzed enantioselective C−H activation has emerged as a versatile platform for constructing point, axial, and planar chirality. Herein, we present an unexpected discovery of a Pd‐catalyzed enantioselective cascade β,γ‐methylene C(sp3)−H diarylation of free carboxylic acids using bidentate chiral mono‐protected amino thioether ligands (MPAThio), enabling one‐step synthesis of a complex chiral 9,10‐dihydrophenanthrene scaffolds with high enantioselectivity. In this process, two methylene C(sp3)−H bonds and three C(sp2)−H bonds were activated, leading to the formation of four C−C bonds and three chiral centers in one pot. A plausible catalytic pathway starts with enantioselective β,γ‐dehydrogenation to form chiral β,γ‐cyclohexene. Intriguingly, this olefin serves as a norbornene‐type reagent (presumably assisted by the carboxyl directing effect), relaying two successive Catellani arylation reactions and a C−H arylation reaction to furnish chiral 9,10‐dihydrophenanthrenes along with meta‐selective homocoupling products of iodoarene. [ABSTRACT FROM AUTHOR]

A new approach for the preparation of a variety of 3-arylated 2-furoic acid derivatives has been developed. The approach involves selective Ru-catalyzed C3-H arylation of the furan moiety of readily available 2-furoyl-1-methylimidazole (using imidazole as a removable N-donor directing group), subsequent N-methylation, and nucleophilic substitution of the imidazole moiety with N, O, S, and C nucleophiles. [ABSTRACT FROM AUTHOR]

In the past few decades, transition-metal-catalyzed direct amination of aryl halides with ammonia has attracted significant attention from chemists because of its broad substrate scope, good functional group compatibility, and high reaction selectivity. Herein, recent examples of transition-metal-catalyzed syntheses of aniline derivatives starting from aryl halides are reviewed. 1 Introduction 2 Heat-Driven Transition-Metal-Catalyzed Amination of Aryl Electrophiles 2.1 Palladium-Catalyzed Amination 2.2 Copper-Catalyzed Amination 2.3 Nickel-Catalyzed Amination 3 Light-Driven Transition-Metal-Catalyzed Amination of Aryl Electrophiles 4 Conclusion and Outlook [ABSTRACT FROM AUTHOR]

We demonstrated that the combination of a Pd(0) catalyst and a water‐soluble TPPMS ligand has high activity for the direct arylation of readily available allylic alcohols in the Tsuji–Trost type cross‐coupling. Various organoboron reagents can be applied, enabling rapid access to the corresponding arylated products with a wide range of functional group tolerance. Kinetic studies revealed a first‐order rate dependence for the allylic alcohol, boronic acid, CsF and Pd(0)/TPPMS concentrations. A Hammett study found a slightly positive ρ value of 0.79, suggesting that a partial negative charge is generated on the aromatic ring of the aryl boronate in the rate‐determining transmetalation step. Based on several control experiments, we concluded that the transmetalation employing CsF would proceed via the oxo‐palladium mechanism. [ABSTRACT FROM AUTHOR]

Indole motifs are omnipresent in nature and can be found in many natural products as well as pharmaceuticals. It is for this reason synthetic transformations of indole have become a topic of interest for the organic and medicinal chemist community for decades. In this review, we have emphasized the functionalization of indoles via transition‐metal‐free approaches. This review touches on many aspects in different sub‐sections, which gives a proposition of the tactics employed for the functionalization of indoles and an overview of the road ahead. [ABSTRACT FROM AUTHOR]

α‐Aryl cyclocarbonyls are important building blocks in organic synthesis. While many methods have been developed for their synthesis, the use of readily available and inexpensive aryl chlorides as the arylating reagent remains rare. Herein, we report an α‐arylation of cyclic ketones with aryl chlorides under reductive electrophotocatalytic conditions. 2,6‐Diisopropylphenyl‐containing naphthalenemonoimide was identified as the optimal electrophotocatalyst, allowing for use of electron‐deficient as well as electron‐rich aryl chlorides under mild conditions. [ABSTRACT FROM AUTHOR]

Carbonyl addition serves as a strategically straightforward and versatile approach for synthesizing alcohols, which are often encountered within bioactive molecules. Herein, we present a ligand‐free, nickel‐catalyzed carbonyl addition process using organoboron reagents. This method enables efficient arylation of readily available ketones or aldehydes, affording a variety of tertiary and secondary alcohols. Key highlights of this protocol include the obviation of external ligands and the tolerance to many functional groups and heterocycles, thereby enhancing its practicality and utility in synthetic organic chemistry. [ABSTRACT FROM AUTHOR]

Directed Pd‐catalysed β‐(hetero)arylation of the 7‐oxabicyclo[2.2.1]heptane framework is described. Arylated products were formed in up to 99 % yield, and heteroarylated products in up to 88 % yield with complete diastereoselectivity. Different minor diarylated side products were formed, depending on whether electron deficient aryl or pyridyl iodides were used as the coupling partners. Cleavage of the 8‐aminoquinoline directing group provided small bridged compounds that may be of value in fragment based drug discovery. [ABSTRACT FROM AUTHOR]

Herein, we report a cross‐coupling reaction between aryl sulfonyl chlorides and arylthianthrenium salts, catalyzed by palladium without ligand. This process involves the desulfonylative of aryl sulfonyl chlorides and pre‐ thianthrenation activation steps of aromatic hydrocarbons, leading to the selective formation of the biaryl compounds. The method demonstrates compatibility with various functional groups. Furthermore, the late‐stage functionalize‐tion of bioactive compounds underscores the favorable implications of this approach in the innovation of novel pharmaceutical agents. [ABSTRACT FROM AUTHOR]

Chemoselective arylation of 5-aminopyrazoles was performed through oxidative formation of orthoquinones from catechols catalyzed by Myceliophthora thermophila laccase (Novozym 51003), and subsequently nucleophilic attack of 5-aminopyrazole to the catechol intermediates. The C-4 arylated products were obtained under extremely mild conditions without the need for amine protection or halogenation of the substrates. From this method, 10 derivatives with moderate to good efficiency (42–94%) were prepared. [ABSTRACT FROM AUTHOR]

Sulfur‐containing functional groups have garnered considerable attention due to their common occurrence in ligands, pharmaceuticals, and insecticides. Nevertheless, enantioselective synthesis of sulfilimines, particularly diaryl sulfilimines remains a challenging and persistent goal. Herein we report a highly enantio‐ and chemoselective cross–coupling of sulfenamides with aryl diazonium salt to construct diverse S(IV) stereocenters by Pd catalysis. Bisphosphine ligands bearing sulfinamide groups play a crucial role in achieving high reactivity and selectivity. This approach provides a general, modular and divergent framework for quickly synthesizing chiral sulfilimines and sulfoximines that are otherwise challenging to access. In addition, the origins of the high chemoselectivity and enantioselectivity were extensively investigated using density functional theory calculations. [ABSTRACT FROM AUTHOR]

A novel class of chain-like multidentate oxalamide ligands with additional coordinating groups was developed for the coupling of (hetero)aryl bromides with both alcohols and phenols under mild conditions. Introduction of oxygen atoms in N-alkyl chains is pivotal for the high catalytic efficiency and broad substrate versatility. [ABSTRACT FROM AUTHOR]

Herein, an operationally simple and mild protocol for defluorinative alkylation and arylation between thianthrenium salts and α-trifluoromethyl alkene with visible light to afford gem-difluoroolefins has been developed. The main feature of this method is avoiding the use of a metal photocatalyst, and an organic photocatalyst is unnecessary for the arylation reaction. In addition, thianthrene can also be recycled and transformed to thianthrenium salts without affecting the efficiency of these reactions. The protocol demonstrates excellent tolerance of functional groups and viable functionalization of late-stage natural products and pharmaceutically relevant molecules. [ABSTRACT FROM AUTHOR]

A visible‐light‐induced, external photocatalyst‐free, site‐selective C−H arylation of 4H‐pyrido[1,2‐a]pyrimidin‐4‐ones and various 2‐aryl heteroarenes has been developed to provide ortho arylated products 41–95% yield at room temperature. A mechanistic study using control experiments, UV‐visible study, DFT study, and observation of colored aggregates suggest that in situ generated Ag‐palladacycle complex of 2‐aryl heteroarenes is responsible for absorbing the visible light and generating aryl radicals from aryldiazonium salts. Further, this methodology demonstrates its versatility by transforming various 2‐aryl heteroarenes, including 2‐phenylquinazolin‐4(3H)‐one, 3‐phenylquinoxalin‐2(1H)‐one, 2‐phenylpyridines, pyrazolo[1,5‐a]pyrimidines, 2‐phenylquinolines, 2‐phenylisoquinolines, and 2‐phenylbenzo[d]thiazoles, into their respective regio‐selective C−H arylated products under mild reaction conditions. [ABSTRACT FROM AUTHOR]

A metallaphotoredox-catalyzed synthesis of heterodiarylmethanes using mild reaction conditions, commercially available substrates, and bench-stable catalysts is demonstrated. Moderate yields are obtained, and further derivatization of the newly formed benzylic position is shown. [ABSTRACT FROM AUTHOR]

This account summarizes the impact that the quest for sustainability is having on the field of organic polyconjugate molecules and polymers for plastic (opto)electronics. While at the proof-of-concept level, the design criteria as well as the preferred synthetic strategies to access new and improved materials have been dominated by the need for performance. The ongoing transition from the lab environment to the industrial scale imposes strict limitations on the cost and overall environmental impact of new materials. We here summarize our efforts on the development of new design criteria and synthetic strategies aimed at improving sustainability – without compromising performance – in organic polyconjugated molecules. The article is composed of three sections: Introduction and motivation, sustainability through improved synthetic methods and through improved design. Outline 1 Introduction and Motivation 2 Sustainable Reaction Methods 2.1 The New Tools: Reactions in Aqueous Solution of Surfactants 2.2 Intrinsically More Sustainable Reactions: Direct Arylation 2.3 Sustainable Multistep Protocols: Combining Micellar, Solventless, and Mechanochemical Methods 3 Sustainability as a Design Criterion: De Novo Design 4 Conclusion [ABSTRACT FROM AUTHOR]