Synthetic strategies to access silacycles

Frontiers in Chemistry, Journal Year: 2023, Volume and Issue: 11

Published: June 15, 2023

In comparison with all-carbon parent compounds, the incorporation of Si-element into carboskeletons generally endows corresponding sila-analogues unique biological activity and physical-chemical properties. Silacycles have recently shown promising application potential in chemistry, pharmaceuticals industry, material chemistry. Therefore, development efficient methodology to assemble versatile silacycles has aroused increasing concerns past decades. this review, recent advances synthesis silacycle-system are briefly summarized, including transition metal-catalytic photocatalytic strategies by employing arylsilanes, alkylsilane, vinylsilane, hydrosilanes, alkynylsilanes, etc. as starting materials. Moreover, a clear presentation understanding mechanistic aspects features these developed reaction methodologies been high-lighted.

Language: Английский

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Construction of Si‐Stereogenic Silanols by Palladium‐Catalyzed Enantioselective C−H Alkenylation

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(20)

Published: Feb. 27, 2024

The construction of silicon-stereogenic silanols via Pd-catalyzed intermolecular C-H alkenylation with the assistance a commercially available L-pyroglutamic acid has been realized for first time. Employing oxime ether as directing group, silanol derivatives could be readily prepared excellent enantioselectivities, featuring broad substrate scope and good functional group tolerance. Moreover, parallel kinetic resolution unsymmetric substrates further highlighted generality this protocol. Mechanistic studies indicate that stabilize Pd catalyst provide chiral induction. Preliminary computational unveil origin enantioselectivity in bond activation step.

Language: Английский

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Enantioselective Copper‐Catalyzed Sequential Hydrosilylation of Arylmethylenecyclopropanes

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: unknown

Published: July 18, 2024

Abstract Despite impressive advances in the construction of enantioenriched silacarbocycles featuring silicon‐stereogenic centers via a selection well‐defined sila‐synthons, development more convenient and economic method with readily available starting materials is significantly less explored remains considerable challenge. Herein, we report first example copper‐catalyzed sequential hydrosilylation accessible methylenecyclopropanes (MCPs) primary silanes, affording an efficient route to wide range chiral silacyclopentanes bearing consecutive silicon‐ carbon‐stereogenic excellent enantio‐ diastereoselectivities (generally ≥98 % ee, >25 : 1 dr). Mechanistic studies reveal that these reactions combine intermolecular ring‐opening aryl MCPs intramolecular asymmetric resultant Z / E mixture homoallylic silanes.

Language: Английский

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Stereoselective Access to Silicon-Stereogenic Silacycles via the Carbene-Catalyzed Desymmetric Benzoin Reaction of Siladials

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(16), P. 9864 - 9871

Published: July 29, 2022

The catalytic asymmetric synthesis of silicon-stereogenic organosilicon compounds has been a long-standing challenging task and was recently accomplished through handful transition-metal-catalyzed approaches. Herein we report an organocatalytic desymmetrization strategy for constructing optically active silacycles. In the presence chiral N-heterocyclic carbene (NHC) catalyst, two identical formyl groups on tetrasubstituted silanes are successfully discriminated to undergo stereoselective intramolecular benzoin reactions, affording enantioenriched dibenzo[b,f]silepin-10-ones featuring carbon- centers at 1,4-positions, respectively. This process can be readily expanded gram scale, products further converted other valuable molecules. DFT calculations were also conducted unveil reaction mechanism origins stereoselectivities.

Language: Английский

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Construction of Tetrasubstituted Silicon-Stereogenic Silanes via Conformational Isomerization and N-Heterocyclic Carbene-Catalyzed Desymmetrization

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(13), P. 7781 - 7788

Published: June 16, 2022

Disclosed here is a catalytic strategy for asymmetric access to chiral tetrasubstituted silicon-stereogenic silanes. Our reaction starts with (covalently) symmetric silane bearing two aldehyde moieties as the substrate. Single-crystal structural analysis shows that substrate exists racemate of conformational enantiomers because presence Si/O weak interaction. Mechanistic studies assisted by DFT calculation indicate can readily isomerize each other, and one favorably activated N-heterocyclic carbene catalyst via an overall desymmetrization process eventually afford optically enriched silanes products. silanes' products be transformed diverse set silicon stereogenic functional molecules.

Language: Английский

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