Search

Comprehensive Summary: Optically active phthalides are prevalent in many natural and bioactive products. Herein, a novel dynamic kinetic resolution of isobenzofuranone derivatives through palladium‐catalyzed asymmetric allylic alkylation has been developed to synthesize phthalide derivatives bearing vicinal quaternary and tertiary stereocenters with high yields, showing excellent chemo‐, enantio‐ and diastereoselectivity. Furthermore, gram‐scale experiment underwent smoothly and the transformation of product could build a bridged bicyclic skeleton. [ABSTRACT FROM AUTHOR]

Photoinduced excited‐state Pd catalysis has emerged as an intriguing strategy for unlocking new reactivity potential of simple substrates. However, the related transformations are still limited and the enantiocontrol remains challenging. Organocatalysis displays unique capability in substrate activation and stereocontrol. Combination of organocatalysis and photoinduced excited‐state Pd catalysis may provide opportunities to develop new enantioselective reactions from simple substrates. By applying cooperative triple catalysis including excited‐state Pd catalysis, ground‐state Pd catalysis, and carbonyl catalysis, we have successfully realized enantioselective α‐allylic alkylation of α‐amino esters with simple styrene and alkyl halide starting materials. The reaction allows rapid modular assembly of the three reaction partners into a variety of chiral quaternary α‐amino esters in good yields with 90–99 % ee, without protecting group manipulations at the active NH2 group. The cooperation of the chiral pyridoxal catalyst and the chiral phosphine ligand accounts for the excellent chirality induction. [ABSTRACT FROM AUTHOR]

An allylic side chain is introduced onto a chiral γ-amino-β-ketoamide by a Pd-catalyzed allylic alkylation. Subsequent ozonolysis and oxidation proceed only with Cbz-protected ketoamides. The total synthesis of moiramide B is finalized by peptide coupling. [ABSTRACT FROM AUTHOR]

A new strategy for the asymmetric allylic alkylation of azlactones with α-(trifluoromethyl)allyl acetates catalyzed by Pd(OAc)2 /(R)-BINAP is designed and developed, providing access to unsaturated α-quaternary α-amino acid derivatives bearing a trifluoromethyl group and contiguous quaternary and tertiary stereogenic centers. The products are obtained in good yields with exclusive regioselectivity and excellent stereoselective control under relatively mild reaction conditions. A scale-up experiment shows no loss of reactivity or stereoselectivity. The synthetic utility of the current strategy is demonstrated through transformations of a representative product to afford several potentially bioactive species. [ABSTRACT FROM AUTHOR]

Transition‐metal‐catalyzed asymmetric α‐allylation of ketones is a particularly useful tool for constructing stereocenters via C−C bond formation. However, this type of reaction often necessitated the use of activated ketones or pre‐prepared enol intermediates as substrates. In this study, we developed a nickel‐catalyzed α‐allylation of unactivated cycloketones with allylic alcohols to synthesize chiral cycloketones with an α‐quaternary carbon center. The reaction affords the products with 42–97% yields, 72–86% ee, and no additive is needed, and the only by‐product is water. [ABSTRACT FROM AUTHOR]

A three‐component allylic alkylation reaction of α‐diazo ketones, water and allyl carbonate under the cooperative catalysis of Rh2(OAc)4, Pd2(dba)3 and Brønsted acid was disclosed. This method provides an expeditious access to α‐keto homoallylic alcohols in good to high yields. Controlled experiments support that the transformations proceed through cross‐interception of two active intermediates Pd‐allyl species and enol intermediates derived from oxonium ylides. Moreover, synthetic transformations of the generated products enable the creation of motifs enriched with dense functional groups, underscoring their potential as valuable building blocks. [ABSTRACT FROM AUTHOR]

The introduction of allyl fluorides as alternative electrophiles in asymmetric allylic alkylation reactions has recently attracted significant interest. Despite the intrinsic thermodynamically demanding C–F bond-cleavage event, the fluorophilic nature of the silicon atom is key in assisting the activation and cleavage of the allylic C–F bond. Thus, the use of silylated compounds as unconventional nucleophiles, together with the Lewis basicity of fluorine when acting as a leaving group, enables the development of innovative chemical transformations within mild and selective catalytic schemes. This Synpacts article summarizes the diverse defluorinative asymmetric allylic alkylations with allyl fluorides reported to date under both chiral Lewis base and transition-metal catalysis. [ABSTRACT FROM AUTHOR]

The prevalence of quaternary stereogenic centers in bioactive molecules coupled with innate challenges associated with their enantioselective preparation continues to provide powerful impetus for the development of catalytic asymmetric methods capable of their construction. Herein, we describe a cooperative isothiourea Lewis base‐palladium catalyst system that enables the enantioselective alkylation of α‐substituted‐α‐cyano esters with allyl methanesulfonate. While the levels of enantioselection are modest, this study represents the first time we have successfully constructed quaternary‐substituted stereogenic centers using this Lewis base‐palladium cooperative catalysis scheme. Further, this strategy constitutes a departure from ligand‐based enantiocontrol and suggests that, when using acidic pro‐nucleophiles, the development of protocols where Lewis base catalysis can outcompete direct deprotonation might be within reach. [ABSTRACT FROM AUTHOR]

Pd‐catalyzed stereoselective glycosylations using unsaturated sugar derivatives, glycals, have been successfully achieved in recent years. This review focuses on approaches to control the stereoselectivities of glycosides via π‐allyl intermediates that mimic the Tsuji–Trost asymmetric allylic alkylation reactions, enabling stereoselectivity control through rational design. In the reaction process, zwitterionic Pd‐π‐allyl complexes, formed after the oxidative addition and decarboxylation, play a crucial role in increasing reactivities and enhancing the stereoselectivities of α‐ and β‐glycosides. We summarized recently developed Tsuji–Trost type glycosylations using 3,4‐carbonate galactals, featuring high efficiency, exclusive stereoselectivities, and a broad reaction scope including O‐, N‐, S‐, and C‐glycosylations. [ABSTRACT FROM AUTHOR]

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

The rising demand and financial costs of noble transition metal catalysts have emphasized the need for sustainable catalytic approaches. Over the past few years, base‐metal catalysts have emerged as ideal candidates to replace their noble‐metal counterparts because of their abundance and easiness of handling. Despite the significant advancements achieved with precious transition metals, earth‐abundant cobalt catalysts have emerged as efficient alternatives for allylic substitution reactions. In this review, allylic alkylations at sp3‐carbon centers mediated by cobalt will be discussed, with a special focus on the mechanistic features, scope, and limitations. [ABSTRACT FROM AUTHOR]

The Pd‐catalysed decarboxylative asymmetric allylic alkylation (DAAA) has been applied to the enantioselective synthesis of sterically hindered benzofuran‐3(2H)‐one‐derived α‐aryl‐β‐keto esters employing the (R,R)‐ANDEN phenyl Trost ligand. A range of substrates were synthesised, employing previously developed aryllead triacetate methodology to install various aryl groups. The resulting α‐aryl‐α‐allyl benzofuran‐3(2H)‐one DAAA products were obtained in moderate to high yields and in enantioselectivities of up to 96 % ee, with the best results observed for substrates containing a di‐ortho‐substitution pattern on the aryl ring as well as naphthyl‐containing substrates. [ABSTRACT FROM AUTHOR]

Highly enantioselective Rh‐catalyzed allylic substitution of the racemic branched allylic substrates with 2‐fluoromalonate was realized enabled by a novel chiral sulfoxide‐imine‐olefin ligand under mild reaction conditions. The utilization of CuSO4 is beneficial for improving the enantioselectivity. Notably, the chiral fluoro‐containing allyl products can be employed in a selective cyclic esterification to form chiral α‐fluorolactone bearing vicinal stereogenic centers. [ABSTRACT FROM AUTHOR]

The migratory insertion of metal-hydride into alkene has allowed regioselective access to organometallics, readily participating in subsequent functionalization as one conventional pathway of hydroalkylation, whereas analogous process with feedstock alkyne is drastically less explored. Among few examples, the regioselectivity of metal-hydride insertion is mostly governed by electronic bias of alkynes. To alter the regioselectivity and drastically expand the intermediate pools that we can access, one aspirational design is through alternative nickel-alkyl insertion, providing opposite regioselectivity induced by steric demand. Leveraging in situ formed nickel-alkyl species, we herein report the regio- and enantioselective hydroalkylation of alkynes with broad functional group tolerance, excellent regio- and enantioselectivity, enabling efficient route to diverse valuable chiral allylic amines motifs. Preliminary mechanistic studies indicate the aminoalkyl radical species can participate in metal-capture and lead to formation of nickel-alkyl, of which the migratory insertion is key to reverse regioselectivity observed in metal-hydride insertion. Although the stereochemistry of nickel hydride addition to alkenes is well-explored, the analogous addition to another feedstock, alkynes, is less studied. Here the authors develop a regio- and enantioselective hydroalkylation of alkynes to produce chiral allylic amines, proceeding via migratory insertion of a nickel–alkyl species into an alkyne pi bond. [ABSTRACT FROM AUTHOR]

A novel strategy that combines oxidative aminocatalysis and gold catalysis allows the preparation of chiral α‐quaternary isochromanes, a motif that is prevalent in natural products and synthetic bioactive compounds. In the first step, α‐branched aldehydes and propargylic alcohols are transformed into α‐quaternary ethers with excellent optical purities (>90 % ee) via oxidative umpolung with DDQ and an amino acid‐derived primary amine catalyst. Subsequent gold(I)‐catalyzed intramolecular hydroarylation affords the isochromane products with retention of the quaternary stereocenter. A second approach explores the use of allylic alcohols as reaction partners for the oxidative coupling to furnish α‐quaternary ethers with generally lower enantiopurities. Stereoretentive cyclization to isochromane products is achieved via intramolecular Friedel‐Crafts type alkylation with allylic acetates as a reactive handle. A number of synthetic elaborations and a biological study on these α‐quaternary isochromanes highlight the potential applicability of the presented method. [ABSTRACT FROM AUTHOR]

The first palladium‐catalyzed allylation of isocyanoacetates with vinyl aziridines has been developed. The reaction conditions were suitable for a variety of α‐aryl isocyanoacetates as well as N‐substituted vinyl aziridines, affording the corresponding allylation products in moderate to high yields (up to 98 %) along with excellent stereoselectivity and regioselectivity. Transformations of the allylation products into trans‐4,5‐dehydrolysine analogues and a highly functionalized proline ester derivative were further demonstrated, and a preliminary asymmetric version of the reaction has also been evaluated. [ABSTRACT FROM AUTHOR]

The Pd‐catalysed decarboxylative asymmetric allylic alkylation (DAAA) of sterically hindered α‐aryl,β‐amido allyl ester lactams has been developed. The key step in the synthesis of a range of α‐aryl lactam substrates for catalysis was a Pb‐mediated α‐arylation of a β‐amido allyl ester affording 14 novel examples of α‐aryl‐β‐amido allyl ester lactams in good yields (up to 80 %). The Pd‐catalysed DAAA was optimised with the 2,4,6‐trimethoxyphenyl‐containing substrate. Using (S,S)‐DACH‐phenyl Trost as the optimal chiral ligand, enantioselectivities of up to 82 % ee were obtained. A substrate scope of 11 examples of α‐aryl‐β‐amido allyl ester lactams showed that products containing the di‐ortho‐methoxy‐substituted phenyls and naphthyl groups gave rise to the highest ees, whereas products not bearing this substitution pattern showed lower enantioselectivities (<60 % ee). Transition states to rationalise the observed stereochemical outcome are proposed. [ABSTRACT FROM AUTHOR]

Alcohol is ubiquitous with unparalleled structural diversity and thus has wide applications as a native functional group in organic synthesis. It is highly prevalent among biomolecules and offers promising opportunities for the development of chemical libraries. Over the last decade, alcohol has been extensively used as an environmentally friendly chemical for numerous organic transformations. In this review, we collectively discuss the utilisation of alcohol from 2015 to 2023 in various organic transformations and their application toward intermediates of drugs, drug derivatives and natural product-like molecules. Notable features discussed are as follows: (i) sustainable approaches for C–X alkylation (X = C, N, or O) including O-phosphorylation of alcohols, (ii) newer strategies using methanol as a methylating reagent, (iii) allylation of alkenes and alkynes including allylic trifluoromethylations, (iv) alkenylation of N-heterocycles, ketones, sulfones, and ylides towards the synthesis of drug-like molecules, (v) cyclisation and annulation to pharmaceutically active molecules, and (vi) coupling of alcohols with aryl halides or triflates, aryl cyanide and olefins to access drug-like molecules. We summarise the synthesis of over 100 drugs via several approaches, where alcohol was used as one of the potential coupling partners. Additionally, a library of molecules consisting over 60 fatty acids or steroid motifs is documented for late-stage functionalisation including the challenges and opportunities for harnessing alcohols as renewable resources. [ABSTRACT FROM AUTHOR]

This article explores the use of thioether-containing ligands in catalysis applications. Thioether ligands, which contain a sulfur atom, have traditionally been less considered due to their lower donor and acceptor character compared to phosphorus ligands. However, ligands with a low degree of oxidation and a combination of sulfur with another heteroatom have shown promise in generating interesting catalysts. The article provides examples of enantioselective and non-enantioselective reactions using thioether ligands and discusses the advantages of combining sulfur with another heteroatom. The paper is organized based on the type of heteroatom that accompanies the thioether function, such as phosphorus and nitrogen. Various catalytic systems involving thioether ligands for different organic transformations are discussed, including dihydroboration, cyclopropanation, silyl-hydrogen insertion, C-H functionalization, and C-H alkenylation. The ligands play a crucial role in enhancing the activity and selectivity of the catalysts, and they have been successfully applied to a wide range of substrates. Mechanistic studies have provided insights into the reaction pathways and the role of the ligands in facilitating the transformations. The article highlights the potential of thioether-functionalized ligands in metal-catalyzed reactions and suggests a promising future for sulfur in catalysis. [Extracted from the article]

Chemical Communications is a journal published by The Royal Society of Chemistry, which aims to connect the world with the chemical sciences. The document provides the contents list for the current issue, including articles on topics such as the design of high-performance layered transition metal oxides for sodium-ion batteries, radical hydroboration for the synthesis of organoboron compounds, and the enantioselective synthesis of tricyclic oxoquinolines. The journal also introduces a new journal called RSC Sustainability GOLD, dedicated to sustainable chemistry and new solutions. The document includes a range of research articles covering various aspects of chemistry. [Extracted from the article]

This article provides an overview of recent advancements in transition-metal-catalyzed Sonogashira cross-coupling reactions of alkyl electrophiles. It discusses the challenges associated with coupling nonactivated alkyl electrophiles and highlights three catalytic systems that have been developed to address these challenges. The article also mentions the development of enantioselective Sonogashira reactions using copper catalysts with chiral ligands. The challenges and future directions in this field are also discussed. [Extracted from the article]

Linearly fused polycyclic piperidines represent common substructures in natural products and biologically active small molecules. We have devised a Pd‐catalyzed annulation strategy to these compounds that converts readily available 2‐tetralones and indanones into these scaffolds with the potential for control of both enantio‐ and diastereoselectivity. Importantly, these compounds can be chemoselectively functionalized, providing an efficient and robust methodology to these important nitrogen‐containing molecules. [ABSTRACT FROM AUTHOR]

The document is a contents list for the journal "Chemical Communications" published in 2024. It includes various articles on topics such as enantioselective merged gold/organocatalysis, the influence of ion and hydration atmospheres on RNA structure and dynamics, NMR analysis of labeled naphthyridine carbamate dimer, and the synthesis of sydnonimines from sydnones. The journal aims to connect the world with the chemical sciences and is published by The Royal Society of Chemistry. [Extracted from the article]

With allyl compounds being a valuable chemical commodity, it is important to understand the sustainability aspects of the Tsuji-Trost reaction in terms of productivity (reactivity-coupled utility), environmental impact (including health hazards), and economic burden and benefits of commercially available allylic precursors under varying conditions. However, comprehensive literature searches reveal that no such study is publicly accessible; the majority of the literature focuses only on the synthetic utility of a few allylic precursors. In this context, we undertook a study for sustainability assessment of 26 allyl precursors (with diverse ionisable partners) by simulating an allylic amination reaction in an alternative reaction medium, water (vs. an organic solvent, OS), under Earth-abundant nickel (vs. traditional palladium) catalysis. The study was accomplished through: (1) conducting reactivity-utility profiling of allylic precursors; (2) identifying the major side reactions occurring with allylic precursors (water vs. OS); and (3) determining green metrics (E-factor, atom economy, atom efficiency, RME, and EcoScale) of the amination process linked with allylic precursors. The key highlights of the study include the following: (a) water is as diverse as an organic solvent in facilitating the Tsuji-Trost allylic amination; (b) diverse allylic precursors could be employed in water as well as in an organic solvent to realize allylic amination; (c) nickel catalysis is a viable alternative to palladium for allylic amination with distinct superiority in the water medium while using an allyl alcohol and allyl amine (trans-N-allylation). Further advancing sustainability and catalysis, we demonstrated for the first time a fully catalytic 'in-water' allylic amination reaction using an allylic alcohol and a Ni(II)-catalyst with features like scale-up synthesis (up to 10 g), catalytic usage of a reductant, etc. The authors propose this work as a sustainability guide to steer further research and developments in academia and industry related to allylation chemistries. [ABSTRACT FROM AUTHOR]

A visible‐light‐induced iron‐catalyzed α‐alkylation of ketones with allylic and propargylic alcohols as pro‐electrophiles is reported. The diaminocyclopentadienone iron tricarbonyl complex plays a dual role by harvesting light and facilitating dehydrogenation and reduction steps without the help of any exogenous photosensitizer. γ,δ‐Unsaturated ketones can now be accessed through this borrowing hydrogen methodology at room temperature. Mechanistic investigations revealed that the steric hindrance on the δ‐position of either the dienone or ene‐ynone intermediate is the key feature to prevent or decrease the competitive 1,6‐reduction (and consequently the formation of the saturated ketone) and to favor the synthesis of a set of non‐conjugated enones and ynones. [ABSTRACT FROM AUTHOR]

To facilitate the discovery and development of new pharmaceuticals, the demand for novel stereofunctionalised building blocks has never been greater. Whilst molecules bearing quaternary and tetrasubstituted stereogenic centres are ideally suited to explore untapped areas of chemical space, the asymmetric construction ofsterically congested carbon centres remains a longstanding challenge in organic synthesis. The enantioselective assembly of acyclic stereogenic centres is even more demanding due to the need to restrict a much wider range of geometries and conformations of the intermediates involved. In this context, the catalytic asymmetric allylicalkylation (AAA) of acyclic prochiral nucleophiles, namely enolates, has become an indispensable tool to access a range of linearα‐quaternary andα‐tetrasubstituted carbonyl compounds. However, unlike the AAA of cyclic enolates with a fixed enolate geometry, to achieve high levels of stereocontrol in the AAA of acyclic enolates, the stereoselectivity of enolisation must be considered. The aim of this review is to offer acomprehensivediscussion of catalytic AAA reactions of acyclic prochiral enolates and their analogues to generate congested quaternary and tetrasubstituted chiral centres using metal, non‐metal and dual catalysis, with particular focus given to the control of enolate geometry and its impact on the stereochemical outcome of the reaction. [ABSTRACT FROM AUTHOR]

The article focuses on supported atomically dispersed palladium (Pd) catalysis for direct alkoxylation and allylic alkylation, emphasizing the catalyst's efficiency and unique mechanism. It discusses the utilization of atomically dispersed Pd on titanium dioxide (TiO2) nanosheets for direct allylic alkylation from allylic alcohols, highlighting the role of hydrogen bonding at the organic-inorganic interface in facilitating the reaction.

Herein, we report an asymmetric two-component alkenyl Catellani reaction for the construction of C--N axial chirality through a palladium/chiral norbornene cooperative catalysis and an axial-to-axial chirality transfer process. Various partially aromatic iodinated 2-pyridones, quinolones, coumarin and uracil substrates react with 2,6-disubstituted aryl bromides with a tethered amide group, to afford a wide variety of polycyclic C--N atropisomers (38 examples, up to 97% e.e.). The obtained C--N axial chirality originates from the preformed transient C--C axial chirality with high fidelity. The synthetic utility of this chemistry is demonstrated by facile preparation of complex quinoline and pyridine based C--N atropisomers through a N-deprotection and aromatization sequence. In addition, a remote axial-to-central diastereoinduction process dictated by C--N axial chirality is observed with excellent diastereocontrol. [ABSTRACT FROM AUTHOR]

An unusual diastereodivergent stereoselective allylation reaction is presented. It consists of a palladium-catalyzed allylation reaction of an organocatalytically generated amino isobenzofulvene, where the diastereoselectivity is controlled by the electronic properties of a monodentate, achiral ligand on palladium. One major diastereoisomer is formed using triarylphosphines substituted with neutral or electron-donating substituents of the aryl group, while those with electron-withdrawing substituents favor the other diastereoisomer. The diastereoselectivity correlates with the Taft inductive parameter of substituents on the triarylphosphine ligand on palladium. The synergistic reaction involves both a catalytic secondary amine catalyst for the indene-aldehyde activation and the monodentate phosphine ligands on palladium, affording a highly enantioselective reaction with up to 98 % enantiomeric excess. Based on computational investigations, the role of the monodentate phosphine ligand on the diastereoselectivity is discussed.

A synergistic chiral primary amine/palladium /p‐hydroquinone catalysis was developed to facilitate oxidative asymmetric allylic C−H alkylation under aerobic conditions. The ternary synergistic catalysis enables a facile allylic C−H activation and alkylation with oxygen so that stoichiometric utilization of benzoquinone can be avoided. The identified optimal catalytic system allows for terminal addition to allyl arenes with α‐branched β‐ketocarbonyls to afford allylic adducts bearing all‐carbon quaternary centers with high regio‐ and enantioselectivity. This work provides new insights for further studies on the aerobically oxidative C−H alkylation reaction. [ABSTRACT FROM AUTHOR]

A catalytic, regioselective Friedel–Crafts alkylation of beta-naphthol with allylic alcohols has been developed. This procedure allows for selective α-alkylation of β-naphthol with a p-toluenesulfonic acid catalyst. This transformation demonstrated functionalized naphthol synthesis under mild reaction conditions with high product yields – 20 examples with up to 96% yields. The synthetic utility further proved the versatility of the allyl naphthol products. [ABSTRACT FROM AUTHOR]

Herein, we report a palladium‐catalyzed atroposelective decarboxylative asymmetric allylic alkylation. A chiral palladium complex with a phosphoramidite ligand effectively desymmetrizes biaryls containing cinnamyl carbonate with excellent enantioselectivities. The addition of a catalytic amount of base accelerates the reaction process without loss of enantioselectivity. Cross‐over experiment provides mechanistic insight, suggesting that allyl palladium complex primarily dissociates from the original biaryl substrate and deliver allyl species intermolecularly. Analysis of product distribution at various time points indicates that secondary kinetic resolution plays a crucial role in achieving remarkable atroposelectivity. [ABSTRACT FROM AUTHOR]

Multicomponent reactions provide an excellent approach toward quaternary carbon centres utilizing convergent chemical reactions in a highly selective manner under one‐pot conditions. The reactivity of substrates and metal catalysts is carefully controlled, precluding the formation of side‐products. In this context, transition metal catalyzed reactions of onium ylides generated via diazo precursors and nucleophiles with a third component (an electrophile) have garnered significant attention. Using an allylic precursor as the electrophilic partner provides opportunities to construct all‐carbon quaternary centres. Furthermore, the presence of an allyl fragment in the multicomponent product serves as a pivotal handle for carrying out subsequent modifications. Several recent studies have employed Rh, Pd, and dual Rh/Pd catalytic systems in multicomponent reactions involving allylic alkylation that proceed via a synergistic or relay pathway. Although not significantly successful, in a few cases, asymmetric induction is achieved through chiral phosphoric acids or chiral phosphine ligands. Limited substrate and catalyst scope and the underlying mechanistic complexities have posed formidable challenges, slowing the advancement of asymmetric reactions. This review provides details of multicomponent reactions using readily available substrates like diazo compounds, allylic carbonates, and nucleophiles (R‐OH, R‐NH2,,etc.) forming complex organic compounds. Our primary objective is to discuss the mechanistic issues that may facilitate the progress in asymmetric reactions in this field. [ABSTRACT FROM AUTHOR]

This review provides an in-depth analysis of recent advances and strategies employed in the Pd-catalysed asymmetric allylic alkylation (Pd-AAA) of nucleophilic prochiral heterocycles. The review is divided into sections each focused on a specific family of heterocycle, where optimisation data and reaction scope have been carefully analysed in order to bring forward specific reactivity and selectivity trends. The review eventually opens on how computer-based technologies could be used to predict an ideally matched catalytic system for any given substrate. This user-guide targets chemists from all horizons interested in running a Pd-AAA reaction for the preparation of highly enantioenriched heterocyclic compounds. [ABSTRACT FROM AUTHOR]

The document is a contents list for the journal Chemical Society Reviews. It highlights various articles and reviews that have been published in the journal. Some of the topics covered include the impact of doping on the mechanical properties of conjugated polymers, ATR-far-ultraviolet spectroscopy, lead-free perovskite solar cells, therapeutic materials for immunoengineering, recent advances in two-dimensional polymers, and more. The journal aims to connect the world with the chemical sciences and is published by The Royal Society of Chemistry. [Extracted from the article]

This article provides an overview of recent advancements in Friedel-Crafts alkylation reactions, specifically focusing on the use of different alkylating agents. It discusses the history and background of the reaction, as well as the use of alcohols, aldehydes, ketones, epoxides, cyclopropanes, and alkyl fluorides as alkylating agents. The article highlights the challenges and limitations of Friedel-Crafts alkylation and suggests future research directions. It also emphasizes the potential applications of this reaction in the synthesis of natural products and complex molecules. Overall, this article serves as a valuable resource for researchers in the field of organic synthesis. [Extracted from the article]

This article provides an overview of the synthesis and applications of planar chiral ferrocene derivatives. It discusses two main approaches to introducing planar chirality in ferrocene compounds: base-mediated ortho-metallation and transition-metal-catalyzed C-H bond activations. These methods allow for the introduction of various functional groups and have applications in asymmetric catalysis, medicinal chemistry, and materials science. The authors, Tomáš Čarný and Radovan Šebesta, are experts in organic chemistry and have conducted research in the field of ferrocene derivatives. [Extracted from the article]

This article explores the synthesis and characterization of Kopsia alkaloids, specifically focusing on the synthesis of kopsinine. The authors discuss the challenges they encountered in the synthesis process and propose alternative strategies for further investigation. The text provides detailed information about the synthesis and characterization of various compounds, including their reaction conditions, yields, and physical properties. This information can be valuable for researchers studying organic chemistry and carbazole derivatives. [Extracted from the article]

This article provides an overview of recent advancements in the synthesis of sulfoxides using sulfenate anions. Sulfoxides are important compounds with various applications, but traditional synthesis methods have limitations. The article focuses on three main areas of transformation: organocatalytic enantioselective alkylation, palladium-catalyzed arylation, and transition-metal-free coupling. It also discusses the precursors of sulfenate anions and their use in synthesis. The article highlights the current scope and limitations of these methods and suggests potential areas for future research, such as metal-free coupling with aryl halides using light and the development of new methods for sulfenate formation. [Extracted from the article]

Metal‐catalyzed asymmetric alkylation of indoles with α‐diazoesters is well‐known, however, the underlying mechanisms of this reaction, particularly the origin of stereoselectivity, remain uncertain. For the Pd catalysis, we address this cutting‐edge challenge from two complementary viewpoints – i) the molecular level regarding a single catalytically active Pd center; and ii) nano‐level Pd species investigating the factors favoring the appearance of the preferred catalytic centers. The formation of the active catalytic species was monitored by structural methods (NMR and ESI‐MS), and metal particles were characterized with electron microscopy (SEM, EDX). On the molecular level, chiral bipyridine‐N,N'‐dioxides proved to be competent chiral controllers. The kinetic and DFT computational data revealed a crucial role of water in the rate and selectivity determining steps and showed that the enantioselectivity of the process is controlled by the protodepalladation step. On the nano‐scale, the important effect of catalyst precursor on the overall reaction performance was shown. [ABSTRACT FROM AUTHOR]

Environmental Engineering Organic Hybrid Functionalized Materials A Pd/phosphoramidite‐selenide‐catalyzed highly enantioselective C‐3 allylic alkylation with a wide range of indole nucleophiles has been developed, giving the corresponding products with up to 95 % yield and 99 % ee. [ABSTRACT FROM AUTHOR]

We present the first solvent‐free, mechanochemical protocol for a palladium‐catalyzed Tsuji–Trost allylation. This approach features exceptionally low catalyst loadings (0.5 mol %), short reaction times (<90 min), and a simple setup, eliminating the need for air or moisture precautions, making the process highly efficient and environmentally benign. We introduce solid, nontoxic, and easy‐to‐handle allyl trimethylammonium salts as valuable alternative to volatile or hazardous reagents. Our approach enables the allylation of various O‐, N‐, and C‐nucleophiles in yields up to 99 % even for structurally complex bioactive compounds, owing to its mild conditions and exceptional functional group tolerance. [ABSTRACT FROM AUTHOR]

This review describes the synthesis of polyphosphorhydrazone (PPH) dendrimers,which are highly branched macromolecules, having a phosphorus atom at each branching point. The properties of these PPH dendrimers in the field of catalysis are then described. The review is organized to illustrate in the first part how the specificities of dendrimers could contribute to green chemistry. This concerns in particular the dendritic effect that is an increased efficiency (yield, enantioselectivity, etc.) when the size of the dendrimer increases, the recovery and reuse of the dendritic catalyst, the decreased leaching, and the entrapping of nanoparticles. In a second part, some even greener approaches of catalysis with dendrimers will be displayed, such as catalysis in water, switchable catalysis, and organocatalysis (nometal used). Different types of catalytic reactions have been studied, such as Stille, Suzuki and Sonogashira couplings, Knoevenagel condensations, Michael additions, asymmetric allylic alkylations, O- and N-arylation and vinylation reactions, [2+2+2]-cycloaddition reactions, isomerization of 1-octan-3-ol, Friedel--Crafts acylations, Heck reactions, hydrogenations, hydrations, transfer hydrogenations, amination of β-dicarbonyl compounds, etc. [ABSTRACT FROM AUTHOR]

Impressive progress has been made in the copper‐catalyzed asymmetric propargylic substitution (APS) reaction, but its use in remote asymmetric yne‐allylic substitution remains a challenging topic. Herein, we report the first remote enantioselective copper‐catalyzed sulfonylation of yne‐allylic esters with sodium sulfinates. The reaction is assumed to occur via a copper‐vinylvinylidene species as the key reactive intermediate. The use of readily available starting materials, the mild reaction conditions, and the excellent regio‐, enantio‐ and stereoselectivity, as well as broad substrate scope (>70 examples), show the practicality and attractiveness of this method. [ABSTRACT FROM AUTHOR]

Alkene planar chirality is introduced in the 'privileged' P-alkene phosphoramidite ligand 1. The resulting diastereomeric ligands (pR,R)-5 and (pS,R)-5 form optically pure complexes of Rh(I) and Pd(II), which catalyze conjugate additions of boron C-nucleophiles to enones and allylic alkylations, respectively. In the Rh-catalyzed reaction, the planar chirality of the alkene exerts absolute enantiocontrol over the potent BINOL auxiliary. [ABSTRACT FROM AUTHOR]

This document discusses the challenges and methods for constructing fluorinated quaternary stereogenic centers in organic molecules, which are important in pharmaceuticals. The authors present a Pd-catalyzed allylic C–H alkylation method using an α-fluoroester for the construction of a C–F quaternary stereogenic center. They found that using a chiral phosphoramidite-palladium catalyst and 2,5-diphenylhydroquinone as an oxidant resulted in high yields and selectivities. The researchers also explored the substrate scope and proposed a plausible reaction mechanism. Overall, this study provides an efficient method for synthesizing fluorinated quaternary stereogenic centers. [Extracted from the article]

The stereocontrolled allylic alkylation of carbonyl compounds with the goal of producing the full range of stereoisomers presents an effective approach for increasing the productivity of collective natural product synthesis and the creation of chiral molecule libraries for drug exploration. The simultaneous control of regio-, diastereo-, and enantioselectivity poses a significant synthetic challenge in contemporary organic synthesis. Herein, we describe a catalytic stereodivergent α-allylation protocol applicable to both aliphatic and aromatic 2-acylimidazoles, thereby providing a practical blueprint for the divergent synthesis of important chiral building blocks. Each of the six isomeric α-allylated compounds can be readily obtained with remarkable yields and exceptional stereoselectivities, by judiciously selecting the appropriate leaving group and permutations of enantiomers adapted from nickel and iridium catalysts. The versatility of this asymmetric allylic alkylation has been successfully utilized in the enantioselective synthesis of (R)-arundic acid and (S,S)-cinamomumolide, as well as in the stereodivergent total synthesis of tapentadol. The simultaneous control of regio-, diastereo-, and enantioselectivity poses a significant synthetic challenge in contemporary organic synthesis. Here, the authors describe a stereodivergent allylation of 2-acylimidazoles using nickel and iridium catalysts to provide completely isomeric allylated compounds. [ABSTRACT FROM AUTHOR]

Beyond the scope of classical Tsuji‐Trost reaction, an alkene bearing a remote leaving group is not considered as a potential substrate for allylation. The concept of migratory Tsuji‐Trost reaction focuses on the transformations with this type of substrates. Two pathways including olefin migration and leaving group migration to form typical allyl intermediate for following substitution have been explored to demonstrate the feasibility of this new concept. [ABSTRACT FROM AUTHOR]

Enantioconvergent catalysis enables the conversion of racemic molecules into a single enantiomer in perfect yield and is considered an ideal approach for asymmetric synthesis. Despite remarkable advances in this field, enantioconvergent transformations of inert tertiary C−H bonds remain largely unexplored due to the high bond dissociation energy and the surrounding steric repulsion that pose unparalleled constraints on bond cleavage and formation. Here, we report an enantioconvergent Pd‐catalyzed alkylation of racemic tertiary allylic C−H bonds of α‐alkenes, providing a unique approach to access a broad range of enantioenriched γ,δ‐unsaturated carbonyl compounds featuring quaternary carbon stereocenters. Mechanistic studies reveal that a stereoablative event occurs through the rate‐limiting cleavage of tertiary allylic C−H bonds to generate σ‐allyl‐Pd species, and the achieved E/Z‐selectivity of σ‐allyl‐Pd species effectively regulates the diastereoselectivity via a nucleophile coordination‐enabled SN2′‐allylation pathway. [ABSTRACT FROM AUTHOR]