Radical Brook rearrangement: past, present, and future

Chemical Society Reviews, Год журнала: 2025, Номер unknown

Опубликована: Янв. 1, 2025

This review aims to provide an overview of radical Brook rearrangement, which is organized by grouping three type reactive species generated via the unique rearrangement process.

Язык: Английский

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Direct C(sp3)-H functionalization with aryl and alkyl radicals as intermolecular hydrogen atom transfer (HAT) agents

Chemical Communications, Год журнала: 2024, Номер unknown

Опубликована: Янв. 1, 2024

Recent years have witnessed the emergence of direct intermolecular C(sp

Язык: Английский

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Pd-Catalyzed Divergent Site-Selective Difluoromethylation and Difluoromethylcarbonylation of Aryl Sulfonium Salts

ACS Catalysis, Год журнала: 2024, Номер 14(18), С. 13557 - 13566

Опубликована: Авг. 28, 2024

The incorporation of the difluoromethyl (CF2H) group into arenes has increasingly been recognized as important in drug discovery. Herein, we report a divergent cross-coupling method for constructing both aryl difluoromethanes and difluoroketones from thianthrenium salts. Site selectivity Negishi-type coupling C1 insertion reactions was achieved under palladium catalysis. Both transformations proceed with broad functional tolerance, enabling late-stage difluoromethylation difluoromethylcarbonylation complex molecules. synthetic utility this demonstrated by synthesizing four pharmaceutical analogues same precursor applying it downstream functionalization difluoroketones.

Язык: Английский

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Palladium-Catalyzed Addition of Trifluoroacetylsilanes to Alkenes and Allenes via the Cleavage of C–Si Bonds

Organic Letters, Год журнала: 2024, Номер 26(10), С. 2141 - 2145

Опубликована: Март 5, 2024

The palladium-catalyzed addition of trifluoroacetylsilanes to alkenes and allenes via the cleavage C–Si bonds is reported. When are used, cyclopropanation occurs afford cyclopropane derivatives bearing CF3 siloxy groups with a high degree stereoselectivity. silylacylation form alkenylsilane trifluoroacetyl group at allylic position complete regioselectivity. Both reactions allow for highly atom-economical access densely functionalized fluorinated organosilane using simple building blocks.

Язык: Английский

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Stereoselective Synthesis of Silyl Enol Ethers with Acylsilanes and α,β-Unsaturated Ketones

Organic Letters, Год журнала: 2024, Номер 26(28), С. 5911 - 5916

Опубликована: Июль 8, 2024

Acylsilanes are emerging bench-stable reagents for the generation of electron-rich oxycarbenes that difficult to access with unstable diazo compounds. Herein, we report a siloxycarbene-mediated stereoselective synthesis silyl enol ethers through visible-light-induced intermolecular reactions between acylsilanes and α,β-unsaturated ketones. Both solvent low temperature important success reaction. This approach features atomic economics, exclusive stereocontrol, broad substrate scope. The synthetic potential this methodology is demonstrated by gram-scale reaction various downstream transformations including requiring configuration purity ethers.

Язык: Английский

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Synthesis of α-SF₅ Ketones by Oxypentafluorosulfanylation of Alkynes with SF₅Cl and Oxygen

Organic Letters, Год журнала: 2025, Номер unknown

Опубликована: Март 18, 2025

Herein for the first time, we disclose a practical and straightforward approach to access α-SF5 ketones via direct oxypentafluorosulfanylation of alkynes with SF5Cl oxygen under acidic conditions by one step. The protocol features mild reaction conditions, broad substrate scope, good functional group compatibility can be applied late-state functionalization complex natural products pharmaceuticals. A radical mechanism involving SF5 addition triple bonds followed O2 capture is proposed.

Язык: Английский

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Asymmetric Trapping of Siloxyketenes In Situ Generated from [1,3]-Silyl Migration of α-Ketoacylsilanes: A Visible-Light-Driven Palladium-Catalyzed [4 + 2] Cycloaddition

ACS Catalysis, Год журнала: 2025, Номер unknown, С. 5796 - 5805

Опубликована: Март 25, 2025

The transition metal-catalyzed asymmetric [n + 2] cycloaddition reaction with oxy-substituted ketene intermediates remains a synthetic challenge due to the limited availability of suitable precursors. Herein, we report visible-light-driven, palladium-catalyzed [4 vinyl benzoxazinanones siloxyketene intermediates, generating structurally diverse chiral quinolinone derivatives satisfactory diastereo- and enantioselectivities. transient generation siloxyketenes from α-ketoacylsilylanes through visible-light-induced Brook rearrangement is important for success present cycloaddition. 13C-labeling experiments reveal pathway involving [1,3]-silyl migration process. side arm effects BOX ligand silyl steric hindrance α-ketoacylsilanes play crucial roles in stereoselectivity control, theoretical calculations provide insights into stereochemical outcome reaction.

Язык: Английский

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Condition‐Controlled Selective Synthesis of CF₃‐Chromene and CF₃‐Benzofuran from N‐Phenoxyacetamide and CF₃‐Ynone

Chinese Journal of Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Март 27, 2025

Comprehensive Summary Presented herein is a condition‐controlled selective synthesis of CF 3 ‐chromene and ‐benzofuran based on the reaction N ‐phenoxyacetamide ‐ynone. When carried out in MeOH under catalysis Rh(III), formed via C—H metalation‐initiated alkenylation, acetamide group migration intramolecular oxo ‐nucleophilic addition. On other hand, when run DMSO promotion CsOAc, generated aza ‐Michael addition‐initiated [3,3]‐σ rearrangement, addition water elimination. To our knowledge, this first report construction chromene or benzofuran scaffold along with introduction unit from same starting materials. The methodology was scalable products could be readily transformed into valuable products. Moreover, thus obtained possess decent anticancer activity.

Язык: Английский

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Fluoroalkylacylsilanes as Novel Ambiphilic Donor–Acceptor Carbene Precursors

Accounts of Chemical Research, Год журнала: 2025, Номер unknown

Опубликована: Апрель 25, 2025

ConspectusCarbenes, as highly reactive intermediates, have emerged pivotal tools in organic synthesis, catalysis, and materials science due to their versatile reactivity broad applicability. Among the diverse classes of carbenes, donor-acceptor carbenes (DACs) attracted significant attention owing unique electronic properties exceptional reaction selectivity. The distinctive DACs arises from synergistic interplay between electron-withdrawing electron-donating groups attached carbene center, enabling a wide array transformations. These attributes established indispensable building blocks for constructing complex molecular architectures achieving precise control over chemical transformation.This Account highlights our recent advancements development fluoroalkylacylsilanes novel precursors DACs. Under photocatalytic conditions, these generate fluoroalkyl siloxycarbenes via radical Brook rearrangement. group, known its strong properties, imparts electrophilic characteristics, while siloxyl group stabilizes center. Together, functionalities render ideal candidates generation DACs, providing platform range transformations, including cycloadditions, bond insertions, construction new structures.First, we developed visible-light-induced, organocatalyzed [2 + 1] cyclization alkynes trifluoroacetylsilanes, leading synthesis cyclopropenols. Mechanistic studies provided compelling evidence involvement triplet intermediates this reaction, demonstrating utility functionalized cyclic compounds. Second, explored cyclopropanation reactions elucidated diastereoselective transfer trifluoroacetylsilane-derived alkenes. Density functional theory (DFT) calculations revealed key insights into origins observed diastereoselectivity, offering molecular-level understanding stereochemical outcomes. Additionally, extended scope include organoboronic esters, divergent ketones. By modulating situ-generated organoboronate complexes─formed through with esters─we achieved selective both fluorine-maintaining defluorinated This transition-metal-free approach is operationally simple compatible substrates, aryl, alkenyl, alkyl boronic esters. Beyond C-B functionalization, applied C(sp2)-H functionalization 1,3-azoles. investigations suggest that success stems dual role trifluoroacetylsilanes under conditions: they not only participate but also produce biradicals facilitate ring-opening aromatization fused cyclopropanes.We anticipate work on ambiphilic will lay groundwork further use acylsilanes chemistry. developments are expected inspire strategies design expand silanes synthetic opening avenues intricate architectures.

Язык: Английский

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Visible-Light-Induced [2 + 2] Cyclization of Alkynes with Bromodifluoroacetylsilanes: Facile Access to gem-Difluorocyclobutenones

Journal of the American Chemical Society, Год журнала: 2025, Номер 147(19), С. 15955 - 15962

Опубликована: Апрель 29, 2025

Herein, we report a simple and efficient method for the synthesis of gem-difluorocyclobutenones from alkynes bromodifluoroacetylsilanes, proceeding via formal cyclization with in situ generated difluoroketene under visible-light-induced conditions. The reaction conditions are mild exhibit broad substrate scope, including both aromatic aliphatic alkynes. Additionally, demonstrates good functional group tolerance, facile scalability, potential diverse downstream transformations. Mechanistic studies suggest that bromodifluoroacetylsilanes act as photochemical precursors to difluoroketene.

Язык: Английский

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