Photocatalytic Z/E isomerization unlocking the stereodivergent construction of axially chiral alkene frameworks

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: April 16, 2024

Abstract The past century has witnessed a large number of reports on the Z / E isomerization alkenes. However, vast majority them are still limited to di- and tri-substituted stereospecific tetrasubstituted alkenes remains be an underdeveloped area, thus lacking in stereodivergent synthesis axially chiral Herein we report atroposelective alkene analogues by asymmetric allylic substitution-isomerization, followed their via triplet energy transfer photocatalysis. In this regard, N -vinylquinolinones is achieved efficiently. Mechanistic studies indicate that benzylic radical generation distribution two key factors for preserving enantioselectivities compounds.

Language: Английский

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Stereoconvergent and -divergent Synthesis of Tetrasubstituted Alkenes by Nickel-Catalyzed Cross-Couplings

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(45), P. 19078 - 19090

Published: Nov. 4, 2021

We report the development of a method to diastereoselectively access tetrasubstituted alkenes via nickel-catalyzed Suzuki-Miyaura cross-couplings enol tosylates and boronic acid esters. Either diastereomeric product was selectively accessed from mixture tosylate starting material diastereomers in convergent reaction by judicious choice ligand conditions. A similar protocol also enabled divergent synthesis each isomer diastereomerically pure tosylates. Notably, high-throughput optimization monophosphine ligands guided chemical space analysis kraken library ensure diverse selection examined. Stereoelectronic results provided insight into requirements for reactive selective this transformation. The synthetic utility optimized catalytic system then probed stereoselective various alkenes, with yields up 94% ratios 99:1 Z/E 93:7 E/Z observed. Moreover, detailed computational experimental mechanistic studies key insights nature underlying isomerization process impacting selectivity cross-coupling.

Language: Английский

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Unlocking Diverse π-Bond Enrichment Frameworks by the Synthesis and Conversion of Boronated Phenyldiethynylethylenes

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(14), P. 10167 - 10176

Published: March 27, 2024

The π-bond enrichment frameworks not only serve as a crucial building block in organic synthesis but also assume pivotal role the fields of materials science, biomedicine, photochemistry, and other related disciplines owing to their distinctive structural characteristics. incorporation various substituents into C═C double bonds tetrasubstituted alkenes is currently highly significant research area. However, with diverse on poses challenge achieving stereoselectivity. Here, we reported an efficient convergent route Cu-catalyzed borylalkynylation both symmetrical unsymmetrical 1,3-diynes, B2pin2, acetylene bromide construction boronated phenyldiethynylethylene (BPDEE) derivatives excellent chemo-, stereo-, regioselectivities. BPDEE could transform novel π-conjugated gem-diphenyldiethynylethylene (DPDEE), vinylphenyldiethynylethylene (VPDEE), phenyltriethynylethylene (PTEE) by stepwise process, which provides flexible platform for complex that were difficult synthesize previous methods. initial optical characterization revealed synthesized molecules exhibited aggregation-induced emission (AIE) properties, further establishes groundwork future applications enriches advances field functional research.

Language: Английский

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Vinyl and Alkynyl Substituted Heterocycles as Privileged Scaffolds in Transition Metal Promoted Stereoselective Synthesis

Accounts of Chemical Research, Journal Year: 2024, Volume and Issue: 57(5), P. 726 - 738

Published: Feb. 22, 2024

ConspectusBiologically active compounds and pharmaceutically relevant intermediates often feature sterically congested stereogenic centers, in particular, carbon stereocenters that are either tertiary tetrasubstituted ones or quaternary nature. Synthons comprise such bulky structurally complex core units of high synthetic value represent important incentives for communities connected to drug discovery development. Streamlined approaches give access a diverse set incorporating acyclic relatively limited, though vital. They enable further exploration three-dimensional entities can be designed implemented programs, thereby extending the pool molecular properties is inaccessible flat molecules. However, lack modular substrates particular areas chemical space inspired us consider functionalized heterocycles known as cyclic carbonates carbamates productive way create crowded alkenes stereocenters.In this Account, we describe major approximations followed over course 8 years using transition metal (TM) catalysis an instrument control stereochemical various allylic propargylic substitution processes related transformations. Allylic reactions empowered by Pd-catalysis utilizing variety nucleophiles discussed, with amination being seed all combined work. These procedures build on vinyl-substituted (VCCs) simple easy-to-access precursors highly nature compared synthetically limited vinyl oxiranes. Overall these decarboxylative conversions take place "linear" "branched" regioselectivities ligand controlled offer wide scope functional scaffolds. Alternative approaches, including dual TM/photocatalyzed transformations, allowed expand repertoire challenging stereoselective conversions. This was achieved through key single-electron pathways via formal umpolung intermediates, resulting new types carbon–carbon bond formation significantly expanding reactions.Heterocyclic substrate variants have triple groups were also difficult-to-promote TM catalysis. In processes, Nishibayashi laboratory their seminal findings area, discovered reactivity patterns. provided range different stereodefined building blocks 1,2-diborylated 1,3-dienes α-allenols under Cu- Ni-catalysis. realm, use lactone-derived gives elusive chiral γ-amino acids lactams stereofidelity good structural diversity.Apart from efforts, elucidated some pertinent mechanistic manifolds operative transformations better understand limitations opportunities specifically synthons. We both theoretical experimental investigations lead several unexpected outcomes terms enantioinduction models, catalyst preactivation, intimately rationales observed selectivity profiles. The work communicated offers insight into unique carbonates/carbamates acting privileged precursors. It may inspire other members widen toward novel added development academic commercial settings.

Language: Английский

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Recyclable Mesoporous Graphitic Carbon Nitride Catalysts for the Sustainable Photoredox Catalyzed Synthesis of Carbonyl Compounds

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(20), P. 13414 - 13422

Published: Oct. 3, 2023

The conversion of feedstock materials into useful chemical compounds through feasible processes is highly sought after from both industrial and environmental perspectives. In this study, we developed a simple scalable protocol for synthesizing aldehydes, ketones, amides abundant raw materials, such as alkanes, alkenes, carboxylic acids. Using photoactive mesoporous graphitic carbon nitride catalyst (mpg-CN) molecular oxygen, successfully transformed over 60 substrates in good yield selectivity. This method suitable the late-stage modification existing drug molecules their corresponding carbonyl derivatives can provide direct access to intermediates or oxidative decomposition degradation products important understanding biological pathways development. Additionally, our applicable large-scale preparation, mpg-CN be recycled without significant loss catalytic activity Comprehensive experiments, including labeled oxygen studies, support photo-oxidative mechanism.

Language: Английский

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Nickel-Catalyzed Asymmetric Cross-Electrophile trans-Aryl-Benzylation of α-Naphthyl Propargylic Alcohols

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(10), P. 6795 - 6803

Published: May 3, 2023

Herein, we report a nickel-catalyzed asymmetric three-component trans-dicarbofunctionalization of β-substituted α-naphthyl propargylic alcohols using readily available aryl and benzyl halides as the coupling partners under reductive conditions. This cross-electrophile strategy enables synthesis various axially chiral allylic bearing tetrasubstituted olefinic unit in complete regio- E selectivity, well high enantiocontrol. Relying on hydroxyl group functional handle, such structural motifs are successfully derivatized into diverse functional-group-rich alkenes.

Language: Английский

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Electrophilic Activation of S−Si Reagents by Silylium Ions for Their Regio‐ and Diastereoselective Addition Across C−C Multiple Bonds

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(15)

Published: Feb. 7, 2024

Abstract A regioselective silylium‐ion‐promoted thiosilylation of internal C−C triple bonds with control over the double bond geometry is described. Both a C(sp 2 )−S and )−Si are formed trans relationship in this two‐component reaction an alkyne thiosilane. The resulting orthogonally functionalized can be chemoselectively defunctionalized or further processed by cross‐coupling reactions alkene configuration retained. procedure also applicable to regio‐ diastereoselective terminal allenes arrive at allylic thioethers containing vinylsilane unit. These involve electrophilic activation S−Si reagent, both silylated thiophenol even alkylthiol derivative, situ‐generated carbocation intermediate. catalytic cycle maintained bissilylated aryl‐ alkylsulfonium ion as shuttle for cationic silicon electrophile. Its independent preparation structural characterization X‐ray diffraction reported.

Language: Английский

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Stereospecific alkenylidene homologation of organoboronates by SNV reaction

Nature, Journal Year: 2024, Volume and Issue: 631(8020), P. 328 - 334

Published: May 23, 2024

Language: Английский

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Catalyst-Free Selective Synthesis of E-Tetrasubstituted Olefins via Tandem Reaction of 3-Acetyl-4-phenyl-1-oxaspiro[4.5]deca-3,6,9-triene-2,8-dione with Amine, C–C Bond Breakage, and Proton Transfer

The Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 25, 2025

The Z- or E-selective syntheses of tetrasubstituted olefins present big challenges. Tremendous efforts are ongoing to overcome this issue, especially for acyclic structures. In work, an E-stereoselective synthetic method through tandem reaction 1,4-Michael addition 3-acetyl-4-phenyl-1-oxaspiro[4.5]deca-3,6,9-triene-2,8-dione with amine, C-C bond breakage, and proton transfer by intermolecular hydrogen bonds was revealed excellent atom economy without catalysts additives. A diverse set E-tetrasubstituted were obtained in 43% 93% yields functional group tolerance late-stage modifications complex drug molecules. mechanism proposed based on the deuterium-labeling experiment density theory (DFT) calculation.

Language: Английский

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Trisubstituted alkenes featuring aryl groups: stereoselective synthetic strategies and applications

Science China Chemistry, Journal Year: 2023, Volume and Issue: 66(5), P. 1261 - 1287

Published: April 17, 2023

Language: Английский

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