Organocatalytic enantioselective construction of Si-stereocenters: recent advances and perspectives

Chemical Society Reviews, Journal Year: 2024, Volume and Issue: 53(17), P. 8546 - 8562

Published: Jan. 1, 2024

Silicon-stereogenic chiral organosilanes have found increasing applications in synthetic chemistry, medicinal and materials science. In this context, various asymmetric catalytic methods been established for the diverse synthesis of silicon-stereogenic silanes. particular, organocatalysis is emerging as an important complementary tool enantioselective construction silicon-stereocenters, along with rapid development chiral-metal catalyzed protocols. Its advent provides a powerful platform to achieve functionalized structural diversity, should lead great organosilicon chemistry. Tutorial Review, we highlight these latest achievements from two aspects: desymmetrizations prochiral tetraorganosilanes dynamic kinetic transformations racemic by employing five organocatalytic activation modes. The advantages, limitations value each protocol, well opportunities still open further exploration, are also discussed.

Language: Английский

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Catalytic Asymmetric Construction of C‐ and Si‐Stereogenic Silacyclopentanes via Hydrosilylation of Arylmethylenecyclopropanes

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(48)

Published: Aug. 14, 2024

Silacycles have exhibited significant potential for application in the fields of medicinal chemistry, agrochemistry, and materials science. Accordingly, development effective methods synthesizing these compounds has attracted increasing attention. Here, we report an efficient Cu-catalyzed enantioselective hydrosilylation arylmethylenecyclopropanes with hydrosilanes, that allows rapid assembly various enantioenriched carbon- silicon-stereogenic silacyclopentanes good yields excellent enantioselectivities diastereoselectivities under mild conditions. Further stereospecific transformation Si-H bond on chiral silicon center expands diversity C- Si-stereogenic silacyclopentanes.

Language: Английский

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Lewis Base-Catalyzed Dynamic Kinetic Asymmetric Transformation of Racemic Chlorosilanes en Route to Si-Stereogenic Silylethers

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(33), P. 23092 - 23102

Published: Aug. 7, 2024

Enantiopure Si-stereogenic organosilanes are highly valued in the fields of organic synthesis, development advanced materials, and drug discovery. However, they not naturally occurring, their synthesis has been largely confined to resolution racemic silanes or desymmetrization symmetric silanes. In contrast, dynamic kinetic asymmetric transformation (DYKAT) offers a mechanistically distinct approach would broaden accessibility an enantioconvergent manner. this study, we report Lewis base-catalyzed DYKAT chlorosilanes. The chiral isothiourea catalyst, (S)-benzotetramisole, facilitates silyletherification with phenols, yielding (R)-silylethers good yields high enantioselectivity (27 examples, up 86% yield, 98:2 er). Kinetic analysis, control experiments, DFT calculations suggest that two-catalyst-bound pentacoordinate silicate is responsible for Si-configurational epimerization ion-paired tetracoordinated silicon intermediates.

Language: Английский

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Nickel-catalyzed cross-electrophile couplings of aryl fluorosulfates with vinyl chlorosilanes

Journal of Catalysis, Journal Year: 2024, Volume and Issue: 437, P. 115636 - 115636

Published: July 6, 2024

Language: Английский

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Enantioselective and Regiodivergent Synthesis of Propargyl‐ and Allenylsilanes through Catalytic Propargylic C−H Deprotonation

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(16)

Published: Feb. 13, 2024

Abstract We report a highly enantioselective intermolecular C−H bond silylation catalyzed by phosphoramidite‐ligated iridium catalyst. Under reagent‐controlled protocols, propargylsilanes resulting from C(sp 3 )−H functionalization, as well the regioisomeric and synthetically versatile allenylsilanes, could be obtained with excellent levels of enantioselectivity good to control propargyl/allenyl selectivity. In case unsymmetrical dialkyl acetylenes, selectivity for functionalization at less‐hindered site was also observed. A variety electrophilic silyl sources (R SiOTf R SiNTf 2 ), either commercial or in situ ‐ generated, were used reagents, broad range simple functionalized alkynes, including aryl alkyl 1,3‐enynes, drug derivatives successfully employed substrates. Detailed mechanistic experiments DFT calculations suggest that an η ‐propargyl/allenyl Ir intermediate is generated upon π‐complexation‐assisted deprotonation undergoes outer‐sphere attack silylating reagent give propargylic silanes, latter step identified enantiodetermining 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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Dynamic Kinetic Activation of Aziridines Enables Radical-Polar Crossover (4 + 3) Cycloaddition with 1,3-Dienes

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 10, 2025

The cycloaddition of aziridines with unsaturated compounds is a valuable method for synthesizing nitrogen heterocycles. However, this process predominantly substrate-controlled, posing significant challenges in regulating the regioselectivity C–N bond cleavage. In study, we report nickel-catalyzed dynamic kinetic activation strategy that enables catalyst-controlled aziridines. Various types aziridines, including 2-phenyl, 2-carbonyl, 2-alkyl, and disubstituted consistently cleave their more sterically hindered bonds to generate 1,3-radical anion intermediates. These intermediates participate highly regioselective 1,4-Heck/allylic substitution cascade aromatic branched 1,3-dienes, resulting radical-polar crossover (4 + 3) produces seven-membered azepine products. This approach not only complements traditional dipolar cycloaddition, which typically act as zwitterionic 1,3-dipoles, but also introduces an unusual mode 1,3-dienes. Experimental investigations density functional theory (DFT) calculations provide insight into reaction mechanism.

Language: Английский

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Ligand Relay for Nickel‐Catalyzed Decarbonylative Alkylation of Aroyl Chlorides

Advanced Science, Journal Year: 2023, Volume and Issue: 11(9)

Published: Dec. 13, 2023

Abstract Transition metal‐catalyzed direct decarboxylative transformations of aromatic carboxylic acids usually require high temperatures, which limit the substrate's scope, especially for late‐stage applications. The development selective decarbonylative acid derivatives, most fundamental aroyl chlorides, with stable and cheap electrophiles under mild conditions is highly desirable meaningful, but remains challenging. Herein, a strategy nickel‐catalyzed alkylation chlorides via phosphine/nitrogen ligand relay reported. simple phosphine found essential decarbonylation step, while nitrogen promotes cross‐electrophile coupling. Such system can effectively orderly carry out catalytic process at room temperature, utilizing easily available as an aryl electrophile reductive alkylation. This discovery provides new coupling, features operationally simple, conditions, excellent functional group tolerance. approach applied to methylation various pharmaceuticals. Extensive experiments are carried provide insights into reaction pathway support process.

Language: Английский

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Achieving Nickel-Catalyzed Reductive C(sp²)–B Coupling of Bromoboranes via Reversing the Activation Sequence

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(11), P. 7210 - 7215

Published: March 4, 2024

Transition metal-catalyzed reductive cross-couplings to build C–C/Si bonds have been developed, but the cross-coupling create C(sp2)–B bond has not explored. Herein, we describe a nickel-catalyzed between aryl halides and bromoboranes construct bond. This protocol offers convenient approach for synthesis of wide range boronate esters, using readily available starting materials. Mechanistic studies indicate that key success reaction is activation B–Br with Lewis base such as 2-MeO-py. The ensures will react active nickel(I) catalyst prior halides, which different from sequence general C(sp2)–C/Si cross-coupling, where oxidative addition an halide proceeds first. Notably, this minimizes production undesired homocoupling byproduct without requirement excessive quantities either substrate.

Language: Английский

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Progress in [4＋1] Cycloadditions of Conjugated Dienes

Chinese Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: 45(1), P. 1 - 1

Published: Jan. 1, 2025

Language: Английский

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