Atropisomers beyond the C–C axial chirality: Advances in catalytic asymmetric synthesis

Chem, Journal Year: 2022, Volume and Issue: 8(7), P. 1855 - 1893

Published: May 6, 2022

Language: Английский

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Organocatalytic Enantioselective Synthesis of Axially Chiral Molecules: Development of Strategies and Skeletons

Accounts of Chemical Research, Journal Year: 2022, Volume and Issue: 55(20), P. 2920 - 2937

Published: Sept. 30, 2022

The growing importance of axially chiral architectures in different scientific domains has unveiled shortcomings terms efficient synthetic access and skeletal variety. This account describes our strategies answering these challenges within the organocatalytic context where emergence bifunctional catalysts such as phosphoric acids (CPAs) proven invaluable controlling sense axial chirality. wide occurrence bi(hetero)aryl skeletons privileged structures constitutes a strong motivation to devise more effective arylation methods. Our design revolves around modulating intrinsic nucleophilicity aromatic amines alcohols. first approach involves an electron-withdrawing activating group which could associate with catalyst for reactivity enhancement selectivity control. resonance arenes offers unique mechanistic possibility select between sites. C2-Azo- nitroso-substituted naphthalenes undergo atroposelective ortho C- or N-arylation (hetero)aromatic nucleophiles. For monocyclic benzenes, programmable charge localization leads regioselective activation by catalytic control alone aided substrate design. instance, selective addition nitroso nitrogen enables successive annulation initiated amine yield N-arylbenzimidazoles. In biomimetic manner, finely tuned direct para-selective nucleophilic azobenzenes. second strategy employs electrophilic arene precursors occurs via rearomatization central-to-axial chirality transfer. enabled (imino)quinones indoles phenylindole atropisomers. By adapting this chemistry additional oxidation event liberate carbonyl functionalities, aryl-o-naphthoquinone aryl-p-quinone atropisomers were attained. Along development new strategies, deriving been another consistent theme research program. functionalization alkynes provides broad entry atropisomeric alkenes. monofunctionalization through interception vinylidene-quinone-methide (VQM) intermediate 2-naphthols yielded EBINOL scaffolds. designing internal directing group, dihalogenation was realized using abundant alkali halides despite their weak nucleophilicities poor solubilities. N-alkylation alkenes pursued prepare multifunctionalized alkene that be converted into 2-arylpyrroles synthesis B-aryl-1,2-azaborines containing C-B axis accomplished CPA effects desymmetrization defines configuration distal bond. Inspired scaffold allenes, we leveraged developed achieve para-addition dearomatization judiciously designed azobenzenes, led structurally novel cyclohexadienylidene-based hydrazones. To complement structures, cyclohexadienyl oxime ethers also attained CPA-catalyzed condensation hydroxylamines spiro[4.5]trienones.

Language: Английский

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Stereoselective construction of atropisomers featuring a C–N chiral axis

Green Synthesis and Catalysis, Journal Year: 2022, Volume and Issue: 3(2), P. 117 - 136

Published: Jan. 4, 2022

Atropisomeric C–N compounds belong to an important class of axially chiral compounds. However, whereas the asymmetric synthesis biaryl atropisomers have been well established, general and efficient strategies access single enantiomers are still rare. Until recently, innovative methods developed, providing new opportunities for highly stereoselective this vital atropisomers. Herein, we comprehensively summarize development in emerging field give some insights into future advance. Emphasis is placed on synthetic strategies.

Language: Английский

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Asymmetric Synthesis of Axially Chiral C−N Atropisomers

Chemistry - A European Journal, Journal Year: 2022, Volume and Issue: 28(28)

Published: Feb. 22, 2022

Molecules with restricted rotation around a single bond or atropisomers are found in wide number of natural products and bioactive molecules as well chiral ligands for asymmetric catalysis smart materials. Although most these compounds biaryls heterobiaryls displaying C-C stereogenic axis, there is growing interest less common more challenging axially C-N atropisomers. This review offers an overview the various methodologies available their synthesis. A brief introduction initially given to contextualize skeletons, including historical background examples containing axes. The preparation different families based then presented from anilides five- six-membered ring heterocycles. Special emphasis has been modern catalytic strategies over past decade synthesis scaffolds. Applications methods biologically active will be highlighted along text.

Language: Английский

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Transition Metal-Catalyzed Biaryl Atropisomer Synthesis via a Torsional Strain Promoted Ring-Opening Reaction

Accounts of Chemical Research, Journal Year: 2022, Volume and Issue: 55(12), P. 1620 - 1633

Published: June 1, 2022

ConspectusArising from the restricted rotation of a single bond caused by steric or electronic effects, atropisomerism is one few fundamental categories for molecules to manifest their three-dimensional characters into which axially chiral biaryl compounds fall. Despite widespread occurrence skeletons in natural products, bioactive molecules, and ligands/organocatalysts, catalytic asymmetric methods synthesis these structures still lag behind demand. Major challenges preparation biaryls include accessing highly sterically hindered variants while controlling stereoselectivity. A couple useful strategies have emerged direct last two decades.Recently, we engaged atropisomers via transition metal catalysis, including ring-openings dibenzo cyclic compounds. During studies, serendipitously discovered that substituents adjacent axis cause be distorted minimize repulsion. The display higher reactivity ring-opening reactions than non-distorted molecules. In other words, torsional strain can promote reaction. On basis this concept, successfully realized reaction diaryliodoniums, silanes, 9H-fluoren-9-ols, delivered several differently substituted ortho tetra-substituted high enantioselectivity. not only activates substrates toward under mild conditions but also changes chemoselectivity bond-breaking events. palladium-catalyzed carboxylation S-aryl dibenzothiophenium, inversed selectivity exocyclic C–S cleavage reaction.In Account, summarize our studies on copper-, rhodium-, as collection straightforward with enantiopurity above-mentioned strain-promoted coupling strategy. part, energies are discussed aid density functional theory (DFT) calculations.

Language: Английский

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Rhodium-Catalyzed Asymmetric C–H Functionalization Reactions

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(16), P. 10079 - 10134

Published: Aug. 1, 2023

This review summarizes the advancements in rhodium-catalyzed asymmetric C–H functionalization reactions during last two decades. Parallel to rapidly developed palladium catalysis, rhodium catalysis has attracted extensive attention because of its unique reactivity and selectivity reactions. In recent years, Rh-catalyzed have been significantly many respects, including catalyst design, reaction development, mechanistic investigation, application synthesis complex functional molecules. presents an explicit outline catalysts ligands, mechanism, scope coupling reagents, applications.

Language: Английский

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Catalytic Asymmetric Synthesis of Axially Chiral 3,3'‐Bisindoles by Direct Coupling of Indole Rings

Chinese Journal of Chemistry, Journal Year: 2022, Volume and Issue: 40(18), P. 2151 - 2160

Published: May 31, 2022

Comprehensive Summary A new strategy for the enantioselective synthesis of axially chiral 3,3'‐bisindoles was devised by direct coupling two indole rings. This makes use C3‐umpolung reactivity 2‐indolylmethanols, which enables catalytic asymmetric addition reaction 2‐indolylmethanols with rationally designed 2‐substituted indoles, thus constructing 3,3'‐bisindole scaffolds in overall excellent yields (up to 98%) high enantioselectivities 96 : 4 er). approach not only has overcome challenges five‐five‐membered heterobiaryls, but also represents a application catalysis. More importantly, this class can undergo variety post‐functionalizations give 3,3'‐bisindole‐based organocatalysts, have found their preliminary applications

Language: Английский

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Cobalt-Catalyzed Enantioselective C–H Arylation of Indoles

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(2), P. 798 - 806

Published: Jan. 10, 2022

Atropoisomeric (hetero)biaryls are scaffolds with increasing importance in the pharmaceutical and agrochemical industries. Although it is most obvious disconnection to construct such compounds, direct enantioselective C–H arylation through concomitant induction of chiral information remains extremely challenging uncommon. Herein, unprecedented earth-abundant 3d-metal-catalyzed atroposelective reported, furnishing rare atropoisomeric C2-arylated indoles. Kinetic studies DFT computation revealed an uncommon mechanism for this asymmetric transformation, oxidative addition being rate- enantio-determining step. Excellent stereoselectivities were reached (up 96% ee), while using unusual N-heterocyclic carbene ligand bearing essential remote substituent. Attractive dispersion interactions along positive C–H---π exerted by identified as key factors guarantee excellent enantioselection.

Language: Английский

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Organocatalytic Enantioselective Synthesis of Axially ChiralN,N′‐Bisindoles

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(15)

Published: Feb. 7, 2023

This study establishes the first organocatalytic enantioselective synthesis of axially chiral N,N'-bisindoles via phosphoric acid-catalyzed formal (3+2) cycloadditions indole-based enaminones as novel platform molecules with 2,3-diketoesters, where de novo indole-ring formation is involved. Using this new strategy, various were synthesized in good yields and excellent enantioselectivities (up to 87 % yield 96 ee). More importantly, class exhibited some degree cytotoxicity toward cancer cells was derived into phosphine ligands high catalytic activity. provides a strategy for using asymmetric organocatalysis realize applications such scaffolds medicinal chemistry catalysis.

Language: Английский

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Enantio‐ and Regioselective Electrooxidative Cobalt‐Catalyzed C−H/N−H Annulation with Alkenes

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(11)

Published: Jan. 20, 2023

In recent years, the merging of electrosynthesis with 3d metal catalyzed C-H activation has emerged as a sustainable and powerful technique in organic synthesis. Despite impressive advantages, development an enantioselective version remains elusive poses daunting challenge. Herein, we report first electrooxidative cobalt-catalyzed enantio- regioselective C-H/N-H annulation olefins using undivided cell at room temperature (up to 99 % ee). t Bu-Salox, rationally designed Salox ligand bearing bulky tert-butyl group ortho-position phenol, was found be crucial for this asymmetric reaction. A strong cooperative effect between Bu-Salox 3,4,5-trichloropyridine enabled highly more challenging α-olefins without secondary bond interactions 96 ee 97 : 3 rr). Cyclovoltametric studies, preparation, characterization, transformation cobaltacycle intermediates shed light on mechanism

Language: Английский

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