X-type silyl ligands for transition-metal catalysis

Chemical Society Reviews, Journal Year: 2024, Volume and Issue: 53(9), P. 4648 - 4673

Published: Jan. 1, 2024

This review summarizes the developments of X-type silyl ligands for transition-metal catalysis, elucidating unique features σ-donating ability and trans -influence silyl–metal catalysts.

Language: Английский

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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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Copper‐Catalyzed Asymmetric Synthesis of Silicon‐Stereogenic Benzoxasiloles

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(7)

Published: Jan. 5, 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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Organocatalytic Si–C_Aryl Bond Functionalization-Enabled Atroposelective Synthesis of Axially Chiral Biaryl Siloxanes

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(37), P. 20646 - 20654

Published: Sept. 11, 2023

Chiral organosilanes are valuable chemical entities in the development of functional organic materials, asymmetric catalysis, and medicinal chemistry. As an important strategy for constructing chiral organosilanes, functionalization Si-CAryl bond typically relies on transition-metal catalysis. Herein, we present efficient method atroposelective synthesis biaryl siloxane atropisomers via organocatalytic Si-C dinaphthosiloles with silanol nucleophiles. The reaction proceeds through protonation simultaneous cleavage/silanolysis sequence presence a newly developed Brønsted acid catalyst. versatile nature streamlines derivatization axially products into other atropisomers, thereby expanding applicability this method.

Language: Английский

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Cobalt-Catalyzed Asymmetric Reductive Alkenylation and Arylation of Heterobiaryl Tosylates: Kinetic Resolution or Dynamic Kinetic Resolution?

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(49), P. 26747 - 26755

Published: Nov. 29, 2023

Herein, we report a cobalt-catalyzed atroposelective reductive cross-coupling of racemic heterobiaryl tosylates with C(sp2)–X type electrophile. Both aryl and alkenyl halides are competent precursors for this reaction, providing variety heterobiaryls as the products in highly enantioselective manner high functionality tolerance. The related asymmetric arylation alkenylation discovered to proceed divergent mechanisms. reaction pathway changes from kinetic resolution (KR) when bromides iodides bearing strong electron-withdrawing substitution on para-position employed starting materials an enantioconvergent transformation via dynamic KR configurationally labile cobaltacycles relatively electron-rich used. change mechanisms turns out arise relative rates two competing elementary steps, which epimerization cyclic Co(I) intermediates their trapping by coupling electrophiles C(sp2)-type oxidative addition.

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

Published: June 15, 2024

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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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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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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Enantioconvergent synthesis of axially chiral amides enabled by Pd-catalyzed dynamic kinetic asymmetric aminocarbonylation

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

Published: Aug. 23, 2024

Atropisomeric biaryls bearing carbonyl groups have attracted increasing attention due to their prevalence in diverse bioactive molecules and crucial role as efficient organo-catalysts or ligands asymmetric transformations. However, preparation often involves tedious multiple steps, the direct synthesis via carbonylation has scarcely been investigated. Herein, we report an palladium-catalyzed enantioconvergent aminocarbonylation of racemic heterobiaryl triflates with amines dynamic kinetic transformation (DyKAT). This protocol features a broad substrate scope excellent compatibility for rapid construction axially chiral amides good high yields enantioselectivities. Detailed mechanistic investigations discover that base can impede intramolecular hydrogen bond-assisted axis rotation products, thus allowing success achieve enantioselectivity. Moreover, achieved be directly utilized N,N,N-pincer copper-catalyzed enantioselective formation C(sp3)-N C(sp3)-P bonds. Axially containing not only exist various drug candidates but also serve authors transformation.

Language: Английский

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Rhodium Complexes with a Pyridine-2-yloxy-silyl-Based N,Si-Ligand: Bonding Situation and Activity as Alkene Hydrogenation Catalysts

Organometallics, Journal Year: 2024, Volume and Issue: 43(3), P. 402 - 413

Published: Jan. 23, 2024

Rh(III) complexes [Rh(H)(X)(κ2-NSitBu2OPy)(L)] (X = Cl, L PCy3, 2a; PHtBu2, 2b; X OTf, 3a; 3b) (NSitBu2OPy 4-methylpyridin-2-yloxy-ditertbutylsilyl) have been prepared and characterized by means of elemental analysis nuclear magnetic resonance (NMR) spectroscopy. The solid-state structures 2a, 2b, 3a determined X-ray diffraction studies. Computational analyses the bonding situation these species evidence electron-sharing nature Rh–Si bond significant role electrostatic component in interaction between transition metal fragment [Rh(H)(PR3)(X)]• [NSitBu2OPy]• ligand. In addition, a comparative study activity 3a, 3b, related iridium as catalysts for hydrogenation olefins has performed. best catalytic results obtained when using with triflate PCy3 ligands, catalyst. density functional theory studies show that formation alkane is thermodynamically favored rate-limiting step corresponds to hydrogen activation, which takes place via σ-complex-assisted metathesis mechanism.

Language: Английский

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