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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Catalytic Kinetic Resolution of Monohydrosilanes via Rhodium‐Catalyzed Enantioselective Intramolecular Hydrosilylation

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(25)

Published: April 12, 2024

The catalytic access of silicon-stereogenic organosilanes remains a big challenge, and largely depends on the desymmetrization symmetric precursors with two identical substitutes attached to silicon atom. Here we report construction via kinetic resolution racemic monohydrosilanes good excellent selectivity factors. Both Si-stereogenic dihydrobenzosiloles could be efficiently accessed in one single operation Rh-catalyzed enantioselective intramolecular hydrosilylation, employing (R,R)-Et-DuPhos as optimal ligand. This protocol features mild conditions, low catalyst loading (0.1 mol % [Rh(cod)Cl]

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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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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Divergent Synthesis of Enantioenriched Silicon‐Stereogenic Benzyl−, Vinyl− and Borylsilanes via Asymmetric Aryl to Alkyl 1,5‐Palladium Migration

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(36)

Published: July 30, 2024

Functionalization of Si-bound methyl group provides an efficient access to diverse organosilanes. However, the asymmetric construction silicon-stereogenic architectures by functionalization has not yet been described despite recent significant progress in producing chiral silicon. Herein, we disclosed enantioselective silylmethyl involving aryl alkyl 1,5-palladium migration naphthalenes possessing enantioenriched stereogenic silicon center, which are inaccessible before. It is worthy note that realization induction at step metal itself remains challenging. Our study constitutes first reaction. The key success discovery and fine-tuning different substituents α,α,α,α-tetraaryl-1,3-dioxolane-4,5-dimethanol (TADDOL)-based phosphoramidites, ensure enantioselectivity desired reactivity.

Language: Английский

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Precise Synthesis of Complex Si–Si Molecular Frameworks

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: 147(4), P. 2938 - 2959

Published: Jan. 16, 2025

In this Perspective, we highlight the emergence of target-oriented syntheses complex molecules composed Si-Si (oligosilanes) rather than C-C bonds. Saturated oligosilanes structurally resemble alkanes with respect to a tetrahedral geometry, preference for staggered conformation in linear chains, ability form stable small rings, and stereochemistry at asymmetrically functionalized Si centers. There are also critical differences, example, differences multiple bonding penta- hexacoordinated structures, that mean chemical reactivity and, particular, rules stereoselective synthesis do not cleanly translate from carbon silicon. This Perspective will discuss recent achievements precise, controlled comprised mainly bonds mechanistic insights enabling increased molecular complexity. New tools, such as electrochemical catalytic reactions, be discussed well problem controlling relative configuration containing stereogenic-at-silicon These synthetic facilitate discovery new properties, including insight into light absorption, conformation, mechanical properties.

Language: Английский

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Enantioselective construction of silicon-stereogenic vinylsilanes from simple alkenes

Nature Communications, Journal Year: 2025, Volume and Issue: 16(1)

Published: Jan. 18, 2025

The diverse utility of acyclic vinylsilanes has driven the interest in synthesis enantioenriched bearing a Si-stereogenic center. However, predominant approaches for catalytic asymmetric generation have mainly relied on transition metal-catalyzed reactions alkynes with different silicon sources. Here we successfully realize enantioselective linear silicon-stereogenic good yields and enantiomeric ratios from simple alkenes under rhodium catalysis. significance this transformation lies its ability to achieve regioconvergent enantioconvergent conversion, efficiently transforming petroleum-derived isomeric mixtures olefin feedstocks into single regio- stereoisomer product. practicality method is further exemplified by downstream transformations these leveraging functionality leaving group nature aryl substituent as well development chiral π-conjugated double bond systems.

Language: Английский

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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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