Catalytic Asymmetric Dehydrogenative Si–H/X–H Coupling toward Si-Stereogenic Silanes

Accounts of Chemical Research, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 22, 2025

ConspectusChiral organosilicon compounds bearing a Si-stereogenic center have attracted increasing attention in various scientific communities and appear to be topic of high current relevance modern organic chemistry, given their versatile utility as chiral building blocks, reagents, auxiliaries, catalysts. Historically, access these non-natural silanes mainly relies on resolution, whereas asymmetric synthetic methods dramatically lagged compared carbon counterparts. Over the past two decades, transition-metal-catalyzed desymmetrization prochiral organosilanes has emerged an effective tool for synthesis enantioenriched silanes. Despite progress, catalytic reactions usually suffer from limited substrate scope, poor functional-group tolerance, low enantioselectivity. The growing demand with structural diversity continued drive development new practical assembly molecules.Five years ago, our research group embarked project aimed at developing general approach that can unlock functionalized efficiency. This Account describes laboratory's endeavor exploration dehydrogenative Si–H/X–H coupling toward features (1) readily accessible dihydrosilane starting materials; (2) diverse X–H (X═C, N, O, etc.) partners; (3) platform transformable monohydrosilane products; (4) efficiency atomic economy.At initial stage research, biaryl was selected model conduct enantioselective intramolecular C–H/Si–H reaction. Rh/Josiphos system found early this process, while final enantiocontrol elusive. Mechanistic studies indicated rhodium silyl dihydride complex is resting state cycle, which may undergo racemization center. Enlightened by mechanistic investigations, strategies, tandem alkene hydrosilylation strategy bulky alkene-assisted strategy, were adopted avoid racemization, delivering corresponding 9-silafluorenes excellent yields enantioselectivities. Further C(sp2)–H or C(sp3)–H silylation gave series five-, six- seven-membered heterocycles Next, we extended reaction intermolecular version, realizing Si–H/C–H, Si–H/O–H, Si–H/N–H variety acyclic monohydrosilanes, ethers, siloxanes, silanols, silazanes. We also presented endeavors apply resulting compounds, including further derivatization, polymerization, chiroptical property successfully introduced Si-stereocenters into bioactive molecules, polymers, materials. Lastly, based understanding metal species, developed type ligand applied enable atroposelective anticipate methodology, insights, studies, will not only inspire chemistry but contribute creation novel molecules medicinal materials science.

Language: Английский

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Construction of axial and point chirality through Ni-catalyzed sila-cycloaddition reaction via desymmetrization and (dynamic) kinetic resolution

Science China Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 6, 2025

Language: Английский

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Recent Progress in the Construction of Silacycles by Transition- Metal-Catalyzed C—H Silylation

Chinese Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: 45(2), P. 423 - 423

Published: Jan. 1, 2025

Language: Английский

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X-Type Silyl Ligands Mediated C—H Functionalization Reactions

Chinese Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: 45(2), P. 641 - 641

Published: Jan. 1, 2025

Language: Английский

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Nickel-Catalyzed Dynamic Kinetic Asymmetric Reductive Arylation of Aldehydes with Heterobiaryl Triflates

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: March 15, 2025

In this context, we report a nickel-catalyzed dynamic kinetic asymmetric reductive arylation of aldehydes with racemic heterobiaryl triflates, offering series axially chiral heterobiaryls bearing centrally secondary alcohol moiety in highly diastereo- and enantioselective manner. The simultaneous control both axial central stereogenic elements the products lies stereoselective nucleophilic addition configurationally labile hetereobiaryl nickel complex to formyl group aldehydes.

Language: Английский

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Copper‐Catalyzed Asymmetric Synthesis of Silicon‐Stereogenic Benzoxasiloles

Angewandte Chemie, Journal Year: 2024, Volume and Issue: 136(7)

Published: Jan. 8, 2024

Abstract A Cu‐catalyzed asymmetric synthesis of silicon‐stereogenic benzoxasiloles has been realized via intramolecular Si−O coupling [2‐(hydroxymethyl)phenyl]silanes. Cu(I)/difluorphos is found to be an efficient catalytic system for enantioselective Si−C bond cleavage and formation. In addition, kinetic resolution racemic substituted [2‐(hydroxymethyl)phenyl]silanes using Cu(I)/ PyrOx (pyridine‐oxazoline ligands) as the developed afford carbon‐ benzoxasiloles. Ring‐opening reactions chiral with organolithiums Grignard reagents yield various enantioenriched functionalized tetraorganosilanes.

Language: Английский

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Organosilicon Precursors for Efficient Aromatic Copper-Mediated Radiocyanation

Published: June 26, 2024

Copper-mediated radiolabelling has revolutionised how (hetero)aromatic imaging agents are prepared for positron emission tomography (PET). Despite advancements, this radiochemistry fails to address critical stability, reactivity, and toxicity concerns encountered in many labelling systems, which paramount safely reproducibly generating patient radiomedicines. To overcome these limitations, a copper-mediated 11C-cyanation reaction is presented that leverages heptamethyltrisiloxanes as (hetero)aryl nucleophiles. Rapid ipso-radiocyanation occurs conversions surpass related precursors while offering stability advantages. Preliminary mechanistic data suggests difluoro(methyl)aryl silane may be generated prior transmetallation. Multiple bioactive scaffolds relevant (pre)clinical PET were labelled showcase the broader significance of protocol, including an automated radiosynthesis -opioid receptor antagonist currently under clinical investigation. Overall, adopting aryl will augment radiochemical space support production nuclear medicines.

Language: Английский

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Advances in Chiral Pincer Complexes: Insights and Applications in Catalytic Asymmetric Reactions

International Journal of Molecular Sciences, Journal Year: 2024, Volume and Issue: 25(19), P. 10344 - 10344

Published: Sept. 26, 2024

Chiral pincer complexes, characterized by their rigid tridentate coordination framework, have emerged as powerful catalysts in asymmetric synthesis. This review provides a comprehensive overview of recent advancements the development chiral pincer-type ligands and corresponding transition metal complexes. We highlight latest progress application across range catalytic reactions, including (transfer) hydrogenation polar non-polar bonds, hydrophosphination, alkynylation, Friedel-Crafts enantioselective reductive cyclization alkynyl-tethered cyclohexadienones, hydrosilylation, well Aza–Morita–Baylis–Hillman reactions. The structural rigidity tunability complexes enable precise control over stereoselectivity, resulting high enantioselectivity efficiency complex molecular transformations. As field advances, innovations ligand design exploration new centers are expected to expand scope utility these catalysts, bearing significant implications for synthesis enantioenriched compounds pharmaceuticals, materials science, beyond.

Language: Английский

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Carbon-silicon-switch effect in enantioselective construction of silicon-stereogenic center from silacyclohexadienones

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

Published: Nov. 15, 2024

Carbon-silicon-switch strategy, replacing one specific carbon atom in organic molecules with a silicon, has garnered significant interest for developing new functional molecules. However, the influence of reaction regarding its selectivity and reactivity by carbon-silicon-switch strategy far less been investigated. Here we discover an unusual effect enantioselective construction silicon-stereogenic center. It is found that there change desymmetrization silacyclohexadienones using asymmetric conjugate addition or oxidative Heck aryl/alkyl nucleophiles when compared their analogues cyclohexadienones. Specifically, leads to reversal enantioselectivity arylzinc as nucleophile same chiral catalyst, results totally different arylboronic acid nucleophile. Control experiments density theory (DFT) calculations have shown comes from unique stereoelectronic feature silicon. Silicon incorporated into place under principle that, given they belong periodic group, could be similar. Here, authors perform desymmetrizations on silacyclohexenone analogue, two substrates yielding opposite enantiomers, showing our understanding similarities atoms incomplete.

Language: Английский

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Catalytic Asymmetric Synthesis of Unnatural Axially Chiral Biaryl δ‐Amino Acid Derivatives via a Chiral Phenanthroline‐Potassium Catalyst‐Enabled Dynamic Kinetic Resolution

Angewandte Chemie, Journal Year: 2024, Volume and Issue: 136(36)

Published: June 15, 2024

Abstract Axially chiral biaryl δ‐amino acids possess significantly different conformational properties and environment from centrally amino acids, therefore, have drawn considerable attention in the fields of synthetic medicinal chemistry. Herein, a novel phenanthroline‐potassium catalyst has been developed by constructing well‐organized axially ligand composed one 1,10‐phenanthroline unit two 1,1′‐bi‐2‐naphthol (BINOL) units. In presence this catalyst, good to excellent yields enantioselectivities (up 99 % yield, 98 : 2 er) achieved ring‐opening alcoholytic dynamic kinetic resolution variety lactams, thereby providing an efficient protocol for catalytic asymmetric synthesis unnatural acid derivatives.

Language: Английский

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