Cu-Catalyzed Diastereo- and Enantioselective Synthesis of Borylated Cyclopropanes with Three Contiguous Stereocenters

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

Published: Jan. 17, 2025

Direct synthesis of enantioenriched scaffolds with multiple adjacent stereocenters remains an important yet challenging task. Herein, we describe a highly diastereo- and enantioselective Cu-catalyzed alkylboration cyclopropenes, less reactive alkyl iodides as electrophiles, for the efficient tetra-substituted borylated cyclopropanes bearing three consecutive stereocenters. This protocol features mild conditions, broad substrate scope, good functional group tolerance, affording array chiral in to high yields excellent enantioselectivities. Detailed mechanistic experiments kinetic studies were conducted elucidate reaction pathway rate-determining step reaction. DFT calculations revealed that π···π stacking interaction between phenyl groups on phosphorus ligand, along smaller distortion CuL-Bpin part, contributed The synthetic utility was showcased by facile some valuable centers.

Language: Английский

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Asymmetric Radical Cyclopropanation of α,β-Unsaturated Amides with α-Boryl and α-Silyl Dibromomethanes via Cr(II)-Based Metalloradical Catalysis

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: 147(9), P. 7282 - 7292

Published: Feb. 20, 2025

Transition-metal-catalyzed asymmetric carbene-transfer reactions represent a powerful strategy for synthesizing chiral cyclopropanes. However, current methods predominantly rely on stabilized carbene-bearing α-π-conjugated groups, restricting access to less carbenes, such as α-silyl and α-boryl carbenes. Herein, we present an unprecedented Cr(II)-based metalloradical system the cyclopropanation of α,β-unsaturated amides with dibromomethanes in presence Mn reducing agent. Employing chromium complex, reaction proceeds under mild conditions, yielding cyclopropanes three contiguous stereocenters high diastereo- enantioselectivities. This method features Cr-catalyzed radical-based stepwise mechanism. The broad substrate scope, encompassing various amides, demonstrates protocol's versatility robustness. Mechanistic insights, supported by experimental computational studies, suggest formation α-Cr(III)-alkyl radical intermediates, delineating pathway distinct from that classical concerted cyclopropanations. approach provides tool highly functionalized cyclopropanes, offering potential applications drug discovery development.

Language: Английский

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Recent advances in the construction of tetracoordinate boron compounds

Chemical Communications, Journal Year: 2023, Volume and Issue: 59(26), P. 3812 - 3820

Published: Jan. 1, 2023

Tetracoordinate boron compounds are a highly important class of molecules, which the key intermediates in many organoboron-related chemical transformations and have unique luminescence properties.

Language: Английский

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Enantioselective α-Boryl Carbene Transformations

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(14), P. 9871 - 9879

Published: March 28, 2024

Carbenes, recognized as potent intermediates, enable unique chemical transformations, and organoborons are pivotal in diverse applications. As a hybrid of carbene the boryl group, α-boryl carbenes promising intermediates for construction organoborons; unfortunately, such hard to access have low structural diversity with their asymmetric transformations largely uncharted. In this research, we utilized cyclopropenes precursors swift synthesis metal carbenes, powerful category chiral organoboron synthesis. These undergo series highly enantioselective transfer reactions, including B–H Si–H insertion, cyclopropanation, cyclopropanation/Cope rearrangement, catalyzed by singular copper complex. This approach opens paths previously unattainable but easily transformable organoborons, expanding both chemistry.

Language: Английский

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Copper(I)‐Catalyzed Asymmetric Hydrophosphination of 3,3‐Disubstituted Cyclopropenes

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(40)

Published: Aug. 18, 2023

Herein, a copper(I)-catalyzed asymmetric hydrophosphination of 3,3-disubstituted cyclopropenes is reported. It provides series phosphine derivatives in high to excellent diastereo- and enantioselectivities. The methodology enjoys broad substrate scope on both diarylphosphines. stereoselectivity attributed the stability Cu(I)-(R,R)-QUINOXP* complex presence stoichiometric HPPh2 produced phosphines, high-performance induction complex. Finally, method used for synthesis new chiral phosphine-olefin compounds built cyclopropane skeleton, one which serves as wonderful ligand Rh-catalyzed conjugate addition phenylboronic acid various α,β-unsaturated compounds.

Language: Английский

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Photocatalyzed regioselective hydrosilylation for the divergent synthesis of geminal and vicinal borosilanes

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: May 2, 2023

Geminal and vicinal borosilanes are useful building blocks in synthetic chemistry material science. Hydrosilylation/hydroborylation of unsaturated systems offer expedient access to these motifs. In contrast the well-established transition-metal-catalyzed methods, radical approaches rarely explored. Herein we report synthesis geminal from α-selective hydrosilylation alkenyl boronates via photoinduced hydrogen atom transfer (HAT) catalysis. Mechanistic studies implicate that α-selectivity originates a kinetically favored addition an energetically HAT process. We further demonstrate selective through allyl 1,2-boron migration. These strategies exhibit broad scopes across primary, secondary, tertiary silanes various boron compounds. The utility is evidenced by multi-borosilanes diverse fashion scaling up continuous-flow synthesis.

Language: Английский

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Copper-Catalyzed Carbonylation Reactions: A Personal Account

Synthesis, Journal Year: 2024, Volume and Issue: 56(17), P. 2595 - 2613

Published: Jan. 9, 2024

Abstract Carbonylation reactions have been widely used to construct carbonyl-containing molecules or carbon enhancement reactions, which are mostly catalyzed by noble metals (Pd, Rh, Ru, Ir). In this review, we introduce the copper-catalyzed carbonylation that developed in our group. Diverse using various substrates, including of C–H activated alkanes, difunctionalization unsaturated C–C bonds, and alkyl halides via radical pathway. 1 Introduction 2 Cu-Catalyzed C(sp 3)–H Bonds 3 Carbonylative Difunctionalization Unsaturated 4 Cu–X (H B) Mediated Acylation with Electrophiles 5 6 Alkyl Halides 7 Other Types Copper-Catalyzed Reactions 8 Conclusion Outlook

Language: Английский

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Catalytic Asymmetric P–H Insertion Reactions

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(36), P. 20031 - 20040

Published: Aug. 29, 2023

Albeit notable endeavors in enantioselective carbene insertion into X–H bonds (X = C, O, N, S, Si, B), the catalytic asymmetric P–H reactions still stand for a long-lasting challenge. By merging transition-metal catalysis with organocatalysis, we achieve scalable transformation between diazo pyrazoleamides and H-phosphine oxides that upon subsequent reduction delivers wide variety of optically active β-hydroxyl phosphine good yields high enantioselectivity. The achiral copper catalyst fosters carbenoid bond, while chiral cinchona alkaloid-derived organocatalyst controls outcome. Density functional theory (DFT) calculations further reveal chelates to organocatalyst, enhances its acidity, accordingly promotes proton transfer. Our work showcases potential combining organocatalysis realize elusive reactions.

Language: Английский

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Asymmetric synthesis of chiral sp3-geminated borylstannyl, borylsilyl, and diboryl compounds

Organic Chemistry Frontiers, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

Chiral sp 3 -geminated bimetallic reagents based on B, Si, and Sn have drawn much attention due to their unique structure reaction mode. This review summarizes the synthesis of nonracemic gem -borylstannyl, -borylsilyl, -diboryl compounds.

Language: Английский

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Cu-Catalyzed Enantioselective Carbene Insertion into Ge–H and Si–H Bonds Enabled by SPSiBox with a Tunable Chiral Pocket

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

Published: April 28, 2025

Here, we report the Cu-catalyzed asymmetric carbene insertion into both Ge-H and Si-H bonds with α-trifluoromethyl diazo compounds, enabled by a class of newly developed C2-symmetrical bisoxazoline ligands. This protocol provides an efficient method for preparation enantioenriched ogranogermanes organosilanes, featuring broad substrate scope, mild reaction conditions, excellent enantioselectivity, low catalyst loading. The key to tolerance is use SPSiBox ligands bearing flexible tunable chiral pocket. Preliminary mechanistic studies computational unveiled origin induction ligands, mechanism insertion. not only new construction trifluoromethyl-containing molecules but also opens avenue Si- Ge-containing functional molecules.

Language: Английский

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