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A cross-coupling reaction of allylic aryl ethers with arylmagnesium reagents was investigated using β-aminoketonato- and β-diketiminato-based pincer-type nickel(II) complexes as catalysts. An β-aminoketonato nickel(II) complex bearing a diphenylphosphino group as a third donor effectively catalyzed the reaction to afford the target cross-coupled products, allylbenzene derivatives, in high yield. The regioselective reaction of a variety of substituted cinnamyl ethers proceeded to give the corresponding linear products. In contrast, α- and γ-alkyl substituted allylic ethers afforded a mixture of the linear and branched products. These results indicated that the coupling reaction proceeded via a π-allyl nickel intermediate.

The present article presents a personal account on the synthesis of heterocycles by the combination of regioselective Pd-catalyzed cross-coupling reactions of polyhalogenated heterocycles, i.e., Suzuki–Miyaura and Sonogashira reactions, with alkyne-carbonyl-metathesis (ACM) reactions. The products, which show interesting optical, electronic or medicinal properties, are not readily available by other methods. [ABSTRACT FROM AUTHOR]

Herein, for the first time, we disclose the gold‐catalyzed alkoxy‐carbonylation of aryl and vinyl iodides utilizing ligand‐enabled Au(I)/Au(III) redox catalysis. The present methodology is found to be general, efficient, employs mild reaction conditions and showcases a broad substrate scope even with structurally complex molecules. Density functional theory (DFT) calculations revealed mechanistic pathways distinct from those of conventional transition metal‐catalyzed carbonylation reactions. [ABSTRACT FROM AUTHOR]

This short review article demonstrates recent techniques for the typical conversion of adamantyl C(sp3)−Br bond to various C−C, C−N, and C−X bonds enabled by multiple conditions and reagents with the use of organometallic reagents. This work mainly focuses on developing a mild and convenient system for the selective preparation of substituted adamantyl zinc and magnesium reagents (Ad‐MX) bearing different functional groups on the adamantyl framework. The adamantane scaffolds were selectively functionalized using a various of catalytic methods, most likely organometallic‐Zn, Mg reagent‐mediated Negishi cross‐coupling reactions, acylation, arylation, thiolation, 1,2/1,4‐addition, alkynylation, amination, halogenation, and allylation, etc. Over the years adamantyl derivatives have been broadly studied in various medicinal applications, drug development, supramolecular chemistry, material science, and nanotechnologies, etc. [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]

While iron‐catalyzed C(sp2)−C(sp3) cross‐couplings have been widely studied and developed in the last decade, alkyl‐alkyl cross‐coupling systems with iron remain underdeveloped despite the importance of C(sp3)−C(sp3) bonds in organic synthesis. A major challenge to the development of these reactions is the current lack of fundamental insight into ligand effects and organoiron intermediates that enable effective alkyl‐alkyl couplings. The current study addresses this longstanding limitation using a combination of 57Fe Mössbauer spectroscopy, SC‐XRD (single‐crystal X‐ray diffraction) and reactivity studies of alkyl‐alkyl coupling with iron‐Xantphos to define the in situ formed iron‐Xantphos intermediates in catalysis. Combined with detailed reactivity studies, the nature of the key mechanistic pathways in catalysis and ligands effects to achieve effective alkyl‐alkyl cross‐coupling over competing β‐H elimination pathways are probed. Overall, these foundational studies provide a platform for future bespoke ligand and pre‐catalyst design for alkyl‐alkyl cross‐coupling methods development with sustainable iron catalysis. [ABSTRACT FROM AUTHOR]

Organoboron compounds are widely utilized in organic synthesis for their diverse reactivity, modular preparation, and stability compared to other classes of organometallic reagents. While organoboron species are commonly employed as nucleophiles in cross‐coupling reactions, their potential as racemic building blocks in enantioconvergent transformations remains largely untapped. Herein, we demonstrate the direct utilization of alkylboronic pinacol esters in intermolecular enantioconvergent transformations. Specifically, this work describes the development and mechanistic study of an enantioconvergent deborylative cyanation enabled by Cu catalysis. This method imparts a high degree of enantioselectivity and tolerates a wide range of common functional groups and heterocycles. The reaction is proposed to proceed through a radical‐relay mechanism. Aniline‐assisted homolysis of the carbon–boron bond results in prochiral alkyl radicals that are functionalized by in situ generated Cu(II)(CN)2 species in an enantioselective fashion. The Cu(II)(CN)2 intermediate was characterized by electron paramagnetic resonance (EPR) spectroscopy, and its electronic structure was probed using density functional theory (DFT) calculations. Computational studies were carried out to corroborate the proposed radical‐relay mechanism. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Recent advances in transition metal‐catalyzed o‐carborane B—H activation have led to the rapid development of various methodologies for cage boron functionalization. For catalytic cage B—H acyloxylation, intermolecular oxygenation gave products with different regioselectivities (B(3)‐, B(4)‐, and B(8,9)‐selectivities). Herein, an efficient palladium‐catalyzed direct cage B(4)–H oxygenation of o‐carboranylacetic acids has been achieved, where the carboxylic group serves as not only a directing group, but also a coupling partner. A wide range of substituted o‐carboranylacetic acids have been cyclized via the formation of B(4)−O bond to give the corresponding γ‐lactones in modest to excellent yields. A Pd(IV) intermediate is proposed to be involved in the catalytic cycle. This work offers valuable references for the BH/OH dehydrocoupling reactions under mild conditions to produce carborane‐featuring functional molecules. [ABSTRACT FROM AUTHOR]

Cross‐coupling of nitriles and alcohols offers an environmentally friendly and atom‐economical method for the synthesis of various valuable compounds. These compounds include α‐alkylated and α‐olefinated nitriles, primary amines, imines, N‐alkylation amines, amides, N‐heterocycles, δ‐hydroxynitriles, olefins, etc. Herein, we have reviewed recent developments (from 2013–date) of transition‐metal‐catalyzed cross‐coupling of nitriles and alcohols. A number of transition metal complexes such as noble metals Ru and Ir, as well as base metals Mn, Fe, Co, and Ni are presented. Moreover, different product types, reaction conditions and mechanisms are discussed to understand the reaction and catalyst development. [ABSTRACT FROM AUTHOR]

Cope rearrangements have garnered significant attention owing to their ability to undergo structural reorganization in stereoselective manner. While substantial advances have been achieved over decades, these rearrangements remained applicable exclusively to parent 1,5‐hexadienes. Herein, we disclose the gold‐catalyzed arylative Cope rearrangement of 1,6‐heptadienes via a cyclization‐induced [3,3]‐rearrangement employing ligand‐enabled gold redox catalysis. Detailed mechanistic investigations including several control experiments, cross‐over experiment, HRMS analysis, 31P NMR and DFT studies have been performed to underpin the mechanism. [ABSTRACT FROM AUTHOR]

Herein, we disclose the first report on gold‐catalyzed C(sp2)‐CN cross‐coupling reaction by employing a ligand‐enabled Au(I)/Au(III) redox catalysis. This transformation utilizes acetone cyanohydrin as a nucleophilic cyanide source to convert simple aryl and alkenyl iodides into the corresponding nitriles. Combined experimental and computational studies highlighted the crucial role of cationic silver salts in activating the stable (P,N)‐AuCN complex towards the oxidative addition of aryl iodides to subsequently generate key aryl‐Au(III) cyanide complexes. [ABSTRACT FROM AUTHOR]

Over the decades, conventional techniques have been reported for the direct conversion of a substantial framework of adamantyl C(sp3)‐H/Br/COOH bonds to various C−C, C−N, and other C−X bonds enabled by various catalytic conditions and reagents. There are various simple and direct methods for converting adamantane tertiary and secondary C‐(Sp3)‐H/X/M bonds to quaternary/ tertiary carbon‐carbon bonds that have been reported in previous years, which include methods such as catalytic approaches, cross‐coupling reactions, C−H bond functionalization, radical reactions, organometallics, and dual catalysis, etc. The selective catalytic techniques published between 2010 and 2023 are covered in this article. These adamantane derivatives are broadly studied in various fields such as medicinal chemistry applications, drug development, supramolecular chemistry, material science, catalysts/ligands, and nanotechnologies. [ABSTRACT FROM AUTHOR]

The high oxidation potential of Au(I)/Au(III) redox couple renders the development of gold‐catalyzed cross‐coupling reactions highly challenging. In the pursuit of Au(I)/Au(III) redox catalysis, various strategies, such as the use of stoichiometric oxidants, merged gold/photoredox systems, or ligand‐enabled approaches, have been adopted to achieve the oxidation of Au(I) to Au(III) complexes. Recently, electrochemical anodic oxidation‐based gold redox catalysis has emerged as a new technique to facilitate gold‐catalyzed cross‐coupling reactions. This concept article provides a succinct overview of electrochemical gold redox catalysis, highlighting the challenges and potential future developments. [ABSTRACT FROM AUTHOR]

Over the decades, functionalized heteroaromatic compounds and their scaffolds have drawn significant attention in synthetic organic chemistry as well as in interdisciplinary sciences due to their prevalence in natural products, hormones, vitamins, and their applications in pharmaceuticals, agrochemicals, veterinary products, dyes and pigments, bio‐imaging, semiconductors, and optoelectronics, etc. This review explores various synthetic strategies for functionalization of numerous 5,6 benzo‐fused heteroaromatic derivatives such as indole, benzofuran, benzothiophene, benzimidazole, benzoxazole, benzothiazole and benzotriazole through various methods including C−H activation, cross‐coupling, metal catalysis, photo‐catalysis, electrocatalysis and organocatalysis in recent years (2019–2023). Highly functionalized heterocyclic scaffolds are the important precursors for synthesizing many bioactive drugs like fenbendazole, viozan, griseofulvin, zileuton, flunoxaprofen, natural products, and optoelectronic materials, etc. [ABSTRACT FROM AUTHOR]

The development of a new and straightforward chemoselective method for the synthesis of uracil-based structures by combining Suzuki–Miyaura and Sonogashira–Hagihara cross-coupling is reported. The methodology was applied to synthesize a series of novel compounds. The tolerance of the combination of different functional groups was tested. The influence of different functional groups on the physical properties was studied by ultraviolet–visible (UV–vis) and fluorescence spectroscopy, providing new insights into the potential applications of uracil-based structures.

Transition metal catalysis allows for the efficient and selective introduction of vinyl moieties onto organic molecules and offers a versatile approach to synthesizing complex organic molecules. Nonetheless, few transition‐metal free vinylation reactions have also been reported, exhibiting exceptional functional group tolerance and circumventing selectivity issues. This review provides an overview of carbon, nitrogen and oxygen vinylation, presenting innovative strategies and key advancements in the field. Hence, it will serve as a valuable resource for organic chemists who are interested in the synthesis of vinyl‐containing compounds. By understanding the diverse strategies involved in vinylation, readers will gain insights into harnessing this powerful synthetic methodology for the efficient construction of carbon‐carbon and carbon‐heteroatom bonds. [ABSTRACT FROM AUTHOR]

Ligands are at the heart of coordination chemistry. They conjure the magic of transition metals expressed in organometallic catalysis. Phosphine or P-ligands have found vast utility in transition metal chemistry, though demanding tedious synthesis. Several N, S-based ligands also find application in organometallic chemistry. Oximes are easily derived from aldehydes and ketones by simple reactions with hydroxylamine. Thus, an extensive library of oximes is available with different structural and electronic variations essential for coordination chemistry and catalysis. Several compounds with complex structural features, unavailable for phosphorous ligands, can be readily converted into active oxime ligands in a single derivatization step. Oxime ligands and metal complexes are applied in synthesizing diverse organic molecules and thus versatile ligands in organotransition metal chemistry. [ABSTRACT FROM AUTHOR]

Diaryl difluoromethanes are valuable targets for medicinal chemistry because they are bioisosteres of diaryl ethers and can function as replacements for diaryl methane, ketone, and sulfone groups. However, methods to prepare diaryl difluoromethanes are scarce, especially methods starting from abundant aryl halides. We report the Pd-catalyzed aryldifluoromethylation of aryl halides with aryldifluoromethyl trimethylsilanes (TMSCF2 Ar). The reaction occurs when the catalyst contains a simple, but unusual, dialkylaryl phosphine ligand that promotes transmetallation of the silane. Computational studies show that reductive elimination following transmetallation occurs with a low barrier, despite the fluorine atoms on the α-carbon, due to coordination of the difluorobenzyl π-system to palladium. The co-development of a cobalt-catalyzed synthesis of the silanes broadened the scope of the process including several applications to the synthesis biologically relevant diaryl difluoromethanes.

This article discusses the development of a clinical compound, PF-06842874, for the treatment of Pulmonary Arterial Hypertension (PAH). The authors focus on the synthesis of the compound and the challenges faced in the process, such as low purity and the use of undesirable solvents. They explore different coupling methods and identify a Pd-catalyzed Buchwald-Hartwig coupling as the most effective approach. The article provides valuable insights into the development of a potential treatment for PAH and describes a robust and scalable process for the synthesis of the compound. [Extracted from the article]

A series of N‐doped Benzo[b]fluoranthenes was synthesized. Specifically varying the position of the Nitrogen atom in all four positions of the bottom ring. In the last reaction step the five‐membered ring of the unsubstituted core structure is formed by palladium catalyzed CH‐activation. This synthetic approach allows for the selective introduction of heteroatoms into the core structure and leads to four regioisomeric products. Subsequently the optical and electrochemical properties of these polyaromatic heterocycles were compared. DFT/TD‐DFT and NICS calculations were performed to further analyze, how the position of Nitrogen impacts the overall characteristics of the molecules. This composes a thorough study on the chemical behavior of N‐doped Benzo[b]fluoranthenes. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Furans bearing alkynyl substituents are highly useful in organic synthesis. However, the methodologies to access these important furan derivatives are rather limited. We herein report an efficient synthesis of alkynylated furan derivatives based on Pd‐catalyzed oxidative cross‐coupling reaction between allenyl ketones and terminal alkynes. This novel synthesis of alkynylated furans with wide substrate scope is operationally simple and tolerates various functional groups. Mechanistically, the formation of the palladium carbene through cycloisomerization and the subsequent alkynyl migratory insertion are proposed as the key steps in the transformation. The reaction reported in this paper further demonstrates the generality of the carbene‐based cross coupling. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Furans bearing alkynyl substituents are highly useful in organic synthesis. However, the methodologies to access these important furan derivatives are rather limited. We herein report an efficient synthesis of alkynylated furan derivatives based on Pd‐catalyzed oxidative cross‐coupling reaction between allenyl ketones and terminal alkynes. This novel synthesis of alkynylated furans with wide substrate scope is operationally simple and tolerates various functional groups. Mechanistically, the formation of the palladium carbene through cycloisomerization and the subsequent alkynyl migratory insertion are proposed as the key steps in the transformation. The reaction reported in this paper further demonstrates the generality of the carbene‐based cross coupling. [ABSTRACT FROM AUTHOR]

α‐Trifluoromethylated ketones have attracted significant attention as valuable building blocks in organic synthesis. Such compounds are generally accessed through trifluoromethylation of ketones. Here we report an alternative disconnection approach for the construction of α‐CF3 carbonyl compounds by using aroyl fluorides as bifunctional reagents for fluoroaroylation of gem‐difluoroalkenes through cooperative photoredox and N‐heterocyclic carbene (NHC) catalysis. This strategy bypasses the use of expensive or sensitive trifluoromethylation reagents and/or the requirement for ketone pre‐functionalization, thus enabling an efficient and general synthetic method to access α‐CF3‐substituted ketones. A wide variety of gem‐difluoroalkenes and aroyl fluorides bearing a diverse set of functional groups are eligible substrates. Notably, the developed methodology also provides rapid access to mono‐ or difluoroalkyl ketones. Mechanistic studies reveal that merging photoredox catalysis with NHC catalysis is essential for the reaction. [ABSTRACT FROM AUTHOR]

The combination of a nickel(II) catalyst and a mechanoredox catalyst under ball‐milling conditions promotes mechanical‐force‐driven C−N cross‐coupling reactions. In this nickel(II)/mechanoredox cocatalyst system, the modulation of the oxidation state of the nickel center, induced by piezoelectricity, is used to facilitate a highly efficient aryl‐amination reaction, which is characterized by a broad substrate scope, an inexpensive combination of catalysts (NiBr2 and BaTiO3), short reaction times, and an almost negligible quantity of solvents. Moreover, this reaction can be readily up‐scaled to the multi‐gram scale, and all synthetic operations can be carried out under atmospheric conditions without the need for complicated reaction setups. Furthermore, this force‐induced system is suitable for excitation‐energy‐accepting molecules and poorly soluble polyaromatic substrates that are incompatible with solution‐based nickel(II)/photoredox cocatalysts. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Rhodium(III)‐catalyzed enantioselective C—H indolylization of isoquinolines was developed. The C—H coupling reactions between 1‐aryl isoquinoline derivatives and 3‐indolylphenyliodonium salts proceeded smoothly in the presence of a modified chiral cyclopentadienyl‐Rh(III) complex, affording a series of axially chiral indolylated biaryl products in excellent yields and enantioselectivity (up to 98% yield and 95% ee). [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Rhodium(III)‐catalyzed enantioselective C—H indolylization of isoquinolines was developed. The C—H coupling reactions between 1‐aryl isoquinoline derivatives and 3‐indolylphenyliodonium salts proceeded smoothly in the presence of a modified chiral cyclopentadienyl‐Rh(III) complex, affording a series of axially chiral indolylated biaryl products in excellent yields and enantioselectivity (up to 98% yield and 95% ee). [ABSTRACT FROM AUTHOR]

A strategy that combines electrochemical synthesis and photoredox catalysis was reported for the efficient synthesis of imines. This approach was demonstrated to be highly versatile in producing various types of imines, including symmetric and unsymmetric imines, by exploring the impact of different substituents on the benzene ring of the arylamine. Additionally, the method was specifically applied to modify N‐terminal phenylalanine residues and was found to be successful in the photoelectrochemical cross‐coupling reaction between NH2‐Phe‐OMe and aryl methylamines, leading to the synthesis of phenylalanine‐containing imines. Therefore, this technique would present a convenient and efficient platform for synthesizing imines, with promising applications in chemical biology, drug development, and organic synthesis. [ABSTRACT FROM AUTHOR]

Glycosyl radical functionalization is one of the central topics in synthetic carbohydrate chemistry. Recent advances in metal‐catalyzed cross‐coupling chemistry and metallaphotoredox catalysis provided powerful platforms for glycosyl radical diversification. In particular, the discovery of new glycosyl radical precursors in conjunction with these advanced reaction technologies have significantly expanded the space for glycosyl compound synthesis. In this Review, we highlight the most recent progress in this area starting from 2021, and the reports included will be categorized based on different reaction types for better clarity. [ABSTRACT FROM AUTHOR]

Gold catalysis has emerged as an efficient tool for the selective functionalisation of C−C multiple bonds. Despite significant progress in this field, the potential of asymmetric gold catalysis has not been fully explored to date. A historical retrospect on the progress in this area reveals that enantioselective gold catalysis is based on three pillars: Au(I) catalysis, Au(III) catalysis, and Au(I)/Au(III) redox catalysis. Irrespective of the mode of catalysis being operative, the design of new ligands is crucial for the development of gold‐catalysed organic transformations. This minireview summarizes the progress made in the development of ligand design for enantioselective Au(I) catalysis, Au(III) catalysis, and Au(I)/Au(III) redox catalysis focusing on the ligands which were specially designed for gold catalysis. [ABSTRACT FROM AUTHOR]

An electrochemical reaction between quinoline N-oxides and morpholine was developed by using Cu(OAc)2 as a catalyst, generating products of 4-aminoquinoline N-oxides in CH2Cl2 or 2-aminoquinoline N-oxides in CH3CN in good yields. With an increase in the amount of electricity passed, the product deoxygenates with the formation of aminoquinolines. The advantages of the reaction are mild conditions, room temperature, the use of morpholine rather than its derivatives, and the ability to control the process when the electrolysis conditions change. Bisubstituted quinoline has also been obtained. The redox properties of both individual participants of C–H/N–H cross-coupling and multicomponent systems were established by voltammetry and EPR methods. For the first time, the EPR spectrum of the morpholine radical was recorded at room temperature, and its magnetic resonance parameters were determined in CH2Cl2. Mechanisms for the catalytic reaction have been proposed. This is a simple and easy-to-perform method for introducing a morpholine substituent, important in medicinal chemistry and other fields, by C–H/N–H cross-coupling. [ABSTRACT FROM AUTHOR]

Here, we report a class of ligands based on oxalohydrazide cores and N-amino pyrrole and N-amino indole units that generates long-lived copper catalysts for couplings that form the C-O bonds in biaryl ethers. These Cu-catalyzed coupling of phenols with aryl bromides occurred with turnovers up to 8000, a value which is nearly two orders of magnitude higher than those of prior couplings to form biaryl ethers and nearly an order of magnitude higher than those of any prior copper-catalyzed coupling of aryl bromides and chlorides. This ligand also led to copper systems that catalyze the coupling of aryl chlorides with phenols and the coupling of aryl bromides and iodides with primary benzylic and aliphatic alcohols. A wide variety of functional groups including nitriles, halides, ethers, ketones, amines, esters, amides, vinylarenes, alcohols and boronic acid esters were tolerated, and reactions occurred with aryl bromides in pharmaceutically related structures.

Reported here is the Pd-catalyzed C-N coupling of hydrazine with (hetero)aryl chlorides and bromides to form aryl hydrazines with catalyst loadings as low as 100 ppm of Pd and KOH as base. Mechanistic studies revealed two catalyst resting states: an arylpalladium(II) hydroxide and arylpalladium(II) chloride. These compounds are present in two interconnected catalytic cycles and react with hydrazine and base or hydrazine alone to give the product. The selectivity of the hydroxide complex with hydrazine to form aryl over diaryl hydrazine was lower than that of the chloride complex, as well as the catalytic reaction. In contrast, the selectivity of the chloride complex closely matched that of the catalytic reaction, indicating that the aryl hydrazine is derived from this complex. Kinetic studies showed that the coupling process occurs by rate-limiting deprotonation of a hydrazine-bound arylpalladium(II) chloride complex to give an arylpalladium(II) hydrazido complex.

A general method for the functionalization of 4a‐aza‐8a‐boranaphthalene in the position β to the nitrogen atom has been developed. This method is based on a regioselective iridium‐catalyzed C−H activation process for the introduction of a boronate group, which can subsequently be transformed into a variety of aryl or alkynyl groups via cross‐coupling reactions. Selective mono‐ or difunctionalization can be achieved by controlling the reaction conditions during the borylation step. The photophysical properties of the obtained 3‐ or 3,6‐substituted BN‐naphthalenes have been evaluated, and some of them have been found to be significantly fluorescent, with fluorescence quantum yields up to 0.85. [ABSTRACT FROM AUTHOR]

We have summarized the developments and advancements of allyl-(aza)allyl coupling reactions in the past years. Since the first report in 1980, Pd-catalyzed allyl-allyl couplings have not drawn chemists' much attention for almost 20 years. Not until the last two decades, transition-metal-catalyzed allyl-(aza)allyl transformations have been retrieved vital interest and significantly developed in many respects, including metal-catalyst, ligand development, mechanistic understanding, substrate scope, and applications in the preparation of complex functional molecules. This review is organized according to the transition metals used in allyl-allyl coupling reactions including our own work. Besides, transition-metal-free, allyl-azaallyl cross-couplings and applications in the total synthesis of natural products and drugs have also been included. [ABSTRACT FROM AUTHOR]

Keywords: cross-coupling; copper; catalysis; heterocycles; alkynes EN cross-coupling copper catalysis heterocycles alkynes 2370 2376 7 07/14/23 20230801 NES 230801 Graph The FDA has approved 37 new drugs and combination therapies in 2022. [13][14][15] Metalloamination/cyclization promoted by diethylzinc proceeded optimally at 90 °C when benzotrifluoride (BTF) was used as the reaction solvent, although toluene and even 1,2-DME can be substituted. The J. Young tube was placed in a 90 °C oil bath and the cyclization reaction was monitored by NMR (indicated by the recession of the alkene peaks), using BTF as an internal standard. [Extracted from the article]

Comprehensive Summary: Alcohols are among the most accessible functionalities. Catalytic deoxygenative functionalization of alcohols is highly synthetically appealing. While significant progress has been made on the reactions with nucleophiles, the reactions with electrophilic coupling partners remain a real challenge. This manuscript highlights the advance in this direction, which is mainly achieved by the first‐row transition metals. The low‐valent titanium catalyst has shown the unique reactivity to homolytically cleave the C—OH bonds. The formed carbon radicals could either undergo reduction to give protonation products or couple with carbon fragments to form C—C bonds. This chemistry is initially realized using a stoichiometric amount of titanium reagents and later extended to catalytic variants. Nickel features a variety of oxidation states ranging from Ni0 to NiIV, and both two‐electron oxidative addition and single‐electron process are involved in their activation of an electrophile. These properties enable nickel to catalyze reductive C—C coupling of alcohols with R–X electrophiles. The reaction is first reported on the reactions of allylic alcohols, then extended to benzylic alcohols and, very recently non‐activated alcohols. Recent effort has resulted in many invaluable methodologies that highly improve the reaction efficiency for the construction of aliphatic C—C bonds. The use of cobalt and copper catalysts not only expands the substrate scope of these reactions but also shows the new reactivity and selectivity issues. [ABSTRACT FROM AUTHOR]

A homogeneous manganese‐catalyzed cross‐coupling of two secondary alcohols for the divergent synthesis of γ‐disubstituted alcohols and β‐disubstituted ketones is reported. Employing the well‐defined Mn‐MACHOPh as the catalyst, this novel protocol has a broad substrate scope with good functional group tolerance and affords a diverse library of valuable disubstituted alcohols and ketones in moderate to good yields. The strong influence of the reaction temperature on the selective formation of alcohol products was theorized in preliminary DFT studies. Studies have shown that the Gibbs free energy of the formation of alcohols is thermodynamically more favourable than corresponding ketones at a lower temperature. [ABSTRACT FROM AUTHOR]

In the current ecological context, use of insect sex pheromones as an alternative to conventional pesticides is in constant growth. In this report, we discuss the recent contributions brought by our groups in the field of iron-catalyzed cross-couplings applied to the synthesis of insect pheromones. The pivotal question of the development of sustainable synthetic procedures involving cheap, non-toxic and efficient additives is also discussed, as well as the mechanistic features guiding the reactivity of such catalytic systems.

We present the first study on the application of platinum complexes in the hydrostannylation of terminal alkynes. A range of platinum complexes were screened, with PtCl2/XPhos proving to provide the best selectivity for the ß-(E)-vinyl stannane. The catalyst system is able to provide the corresponding vinyl stannane in selectivities which surpasses that which is typically afforded under palladium catalysis. Additionally, a telescoped hydrometallation/cross-coupling sequence has been developed, allowing for application of the vinyl stannanes without excessive manipulation or purification of the intermediate stannane. [ABSTRACT FROM AUTHOR]

Transition‐metal‐catalyzed asymmetric carbon−carbon bond formation to forge phosphonates with an α‐chiral carbon center through C(sp3)−C(sp3) and C(sp2)−C(sp3) couplings has been successful. However, the enantioselective C(sp)−C(sp3) coupling has not yet been disclosed. Reported herein is an unprecedented enantioconvergent cross‐coupling of alkynyl bromides and α‐bromo phosphonates to deliver chiral α‐alkynyl phosphonates. [ABSTRACT FROM AUTHOR]

In recent years, gold catalysis involving Au(I)/Au(III) redox cycle has gained significant attention. This account summarizes our contributions to the development of Au(I)/Au(III) catalysis, focusing on cross-coupling reactions and 1,2-difunctionalization reactions of C–C multiple bonds. A special emphasis has been given to understanding the mechanism of the reactions. 1 Introduction 2 Gold-Catalyzed Cross-Coupling Reactions 3 Gold-Catalyzed 1,2-Difunctionalization of C–C Multiple Bonds 4 Conclusion and Outlook [ABSTRACT FROM AUTHOR]

Carbon–carbon and carbon–heteroatom bond-formation reactions catalyzed by benign and inexpensive metals are of much interest in organic synthesis, as these reactions provide green and cost-effective routes. This account summarizes our recent contributions to the construction of carbon–carbon and carbon–heteroatom bonds by using benign-metal catalysts. A number of carbon–heteroatom bond formations, including C–N, C–O, C–S, C–Se, C–Te, and C–P bond formations, are discussed. Mechanistic insights into several reactions are also reported 1 Introduction 2 C–C Bond Formation 3 C–N and C–O Bond Formation 4 Carbon–Chalcogen (C–S, C–Se, C–Te) and C–P Bond Formation 5 Conclusions [ABSTRACT FROM AUTHOR]

Palladium‐catalyzed C−N bond activation of amide is a important but very challenging research area in organic chemistry. This reaction represents a powerful and straightforward method for the preparation of various carbonyl compounds under mild reaction conditions. One notable advancement in this area is related to the design and development of multifunctional NHC ligands and other throw‐away ligands. The reasonable design of ligands could not only improve the activity of catalyst, but also help to adjust the reaction selectivity. In this review, we summarized the structure‐activity relationship of those catalysts with different ligand skeletons and their applications in cross‐coupling reactions including Suzuki‐Miyaura coupling, Buchwald‐Hartwig amination and direct C−H acylation, via amide C−N bond activation. On this basis, we analyze the current bottlenecks encountered in Pd‐NHC‐catalyzed amide C−N activation reactions, and envisage the future development of this field. [ABSTRACT FROM AUTHOR]

An alkoxycarbonyl radical cyclization-cross-coupling cascade has been developed that allows functionalized γ-butyrolactones to be prepared in one step from simple tertiary alcohol-derived homoallylic oxalate precursors. The reaction succeeds with aryl and vinyl electrophiles and is compatible with heterocyclic fragments in both coupling partners. This chemistry allows for the rapid construction of spirolactones, which are of interest in drug discovery endeavors.

Recent advances in heterobimetallic chemistry have revealed the potential for mixed-metal systems to facilitate reactions that are unattainable with their single-metal components. This perspective explores the pairing of nickel(0) complexes with organo-alkali-metal reagents, which yield highly reactive alkali-metal nickelates. These previously underexplored systems have re-emerged as a promising area of research, with recent studies uncovering their unique bonding and structural motifs. Furthermore, the discovery of nickelates as potential intermediates in cross-coupling reactions has provided the foundation for the development and mechanistic understanding of stoichiometric and catalytic transformations.

Comprehensive Summary: Here, we demonstrate a readily prepared anthrazoline photocatalyst, which can effectively promote C—O bond formation reactions with the aid of Ni(II) complex. This methodology enables the esterification (36 examples) and etherification (8 examples) with a broad range of scope, allowing aryl and alkyl halides coupled with diverse carboxylic acids/alcohols. Our metal‐free photocatalysts have a potential broad application, may serve as an alternative to some iridium and ruthenium based photocatalysts, and are of potential importance to the pharmaceutical industry. [ABSTRACT FROM AUTHOR]

While vinyl cyclopropanes are valuable functional groups in drugs or natural products as well as established precursors to trigger a rich variety of synthetic transformations, their reactive nature can make their installation via direct catalytic approaches challenging. We herein present a modular access to (di)vinyl cyclopropanes under very mild conditions and full conservation of stereochemistry, allowing access to the cis or trans cyclopropane‐ as well as E or Z vinyl‐stereochemical relationships. Our protocol relies on air‐stable dinuclear PdI catalysis, which enables rapid (<30 min) and selective access to a diverse range of vinyl cyclopropane motifs at room temperature, even on gram scale. [ABSTRACT FROM AUTHOR]

Herein, we report visible light‐promoted single nickel catalysis for diverse carbon–heteroatom couplings under mild conditions. This mild, general, and robust method to couple diverse nitrogen, oxygen, and sulfur nucleophiles with aryl(heteroaryl)/alkenyl iodides/bromides exhibits a wide functional group tolerance and is applicable to late‐stage modification of pharmaceuticals and natural products. On the base of preliminary mechanistic studies, a NiI/NiIII cycle via the generation of active NiI complexes that appear from homolysis of NiII−I rather than NiII−aryl bond was tentatively proposed. [ABSTRACT FROM AUTHOR]