Rapid and Modular Access to Quaternary Carbons from Tertiary Alcohols via Bimolecular Homolytic Substitution

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(30), P. 16330 - 16336

Published: July 20, 2023

Quaternary carbons are ubiquitous in bioactive molecules; however, synthetic methods for the construction of this motif remain underdeveloped. Here, we report synthesis quaternary from tertiary alcohols, a class structurally diverse, bench-stable feedstocks, via merger photoredox catalysis and iron-mediated SH2 bond formation. This alcohol-bromide cross-coupling is enabled by novel halogen-atom transfer (XAT) reagent, which first reductively activated XAT reagent to be reported. A wide variety sterically congested products can accessed through mild practical protocol including derived both alkylation benzylation fragments. We further demonstrate utility method expedited liver receptor agonist two-step conversion ketones esters products, enables modular control up three four substituents on center.

Language: Английский

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γ-Amino Alcohols via Energy Transfer Enabled Brook Rearrangement

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(15), P. 10899 - 10907

Published: April 3, 2024

In the long-standing quest to synthesize fundamental building blocks with key functional group motifs, photochemistry in recent past has comprehensively established its attractiveness. Amino alcohols are not only functionally diverse but ubiquitous biologically active realm of compounds. We developed bench-stable bifunctional reagents that could then access sparsely reported γ-amino directly from feedstock alkenes through energy transfer (EnT) photocatalysis. A designed 1,3-linkage across is made possible by intervention a radical Brook rearrangement takes place downstream EnT-mediated homolysis our reagent(s). combination experimental mechanistic investigations and detailed computational studies (DFT) indicates chain propagated reaction pathway.

Language: Английский

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Radical Brook rearrangement: past, present, and future

Chemical Society Reviews, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 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.

Language: Английский

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Recent progress and perspectives in photo-induced organic reactions of acylsilanes

Organic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 10(3), P. 819 - 836

Published: Jan. 1, 2023

This review provides recent advances and insights into photoirradiation reactions of acylsilanes, notably via key nucleophilic siloxycarbene intermediates. Nucleophilic addition, insertion reaction, cyclization are discussed in terms reaction mechanism scope.

Language: Английский

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Photoinduced activation of alkyl chlorides

Chemical Society Reviews, Journal Year: 2023, Volume and Issue: 52(17), P. 6120 - 6138

Published: Jan. 1, 2023

In recent years, the activation of unactivated alkyl chlorides through light-induced processes has emerged as a promising field in radical chemistry, and led to new transformations organic synthesis. Direct utilization C(sp3)-hybridized electrophiles enables facile construction carbon-carbon carbon-heteroatom bonds. Furthermore, studies medicinal chemistry indicate that their presence is associated with high levels success clinical trials. This review summarizes advances photoinduced discusses mechanistic aspects underlying these reactions. We anticipate this will serve valuable resource for researchers chemical bond functionalization, inspire considerable developments drug synthesis, materials science other related disciplines.

Language: Английский

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Diverse Alkyl–Silyl Cross-Coupling via Homolysis of Unactivated C(sp³)–O Bonds with the Cooperation of Gold Nanoparticles and Amphoteric Zirconium Oxides

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(8), P. 4613 - 4625

Published: Feb. 20, 2023

Since C(sp3)–O bonds are a ubiquitous chemical motif in both natural and artificial organic molecules, the universal transformation of will be key technology for achieving carbon neutrality. We report herein that gold nanoparticles supported on amphoteric metal oxides, namely, ZrO2, efficiently generated alkyl radicals via homolysis unactivated bonds, which consequently promoted C(sp3)–Si bond formation to give diverse organosilicon compounds. A wide array esters ethers, either commercially available or easily synthesized from alcohols participated heterogeneous gold-catalyzed silylation by disilanes alkyl-, allyl-, benzyl-, allenyl silanes high yields. In addition, this novel reaction could applied upcycling polyesters, i.e., degradation polyesters synthesis organosilanes were realized concurrently unique catalysis nanoparticles. Mechanistic studies corroborated notion generation is involved coupling cooperation an acid–base pair ZrO2 responsible stable bonds. The reusability air tolerance catalysts as well simple, scalable, green system enabled practical

Language: Английский

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Diastereoselective Synthesis of Monofluorocyclohexenes through Photocatalyzed Cascade Cyclization of gem‐Difluoroalkenes and α,β‐Unsaturated Carbonyl Compounds

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(20)

Published: March 16, 2023

Monofluoroalkenes are nonhydrolyzable mimetics of amides. Previous work focused on the synthesis non-cyclic monofluoroalkenes. However, diastereoselective monofluorocyclohexenes from substrates is challenging. Herein, we report first photocatalyzed cascade cyclization reactions readily available α,β-unsaturated carbonyl compounds and gem-difluoroalkenes for highly functionalized monofluorocyclohexenes. The reaction shows broad substrate scope with high diastereoselectivity (>30 examples, up to 86 % yield, >20 : 1 dr). post-reaction transformations products demonstrate synthetic potential this methodology.

Language: Английский

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E‐Selective Radical Difunctionalization of Unactivated Alkynes: Preparation of Functionalized Allyl Alcohols from Aliphatic Alkynes

Advanced Science, Journal Year: 2024, Volume and Issue: 11(16)

Published: Feb. 13, 2024

Abstract Radical difunctionalization of aliphatic alkynes provides direct access to valuable multi‐substituted alkenes, but achieving a high level chemo‐ and stereo‐control remains formidable challenge. Herein novel photoredox neutral alkyne di‐functionalization is reported through functional group migration followed by radical‐polar crossover energy transfer‐enabled stereoconvergent isomerization alkenes. In this sequence, hydroxyalkyl an aryl are incorporated concomitantly into alkyne, leading diversely functionalized E‐allyl alcohols. The scope noteworthy, the reaction tolerates containing hydrogen donating C─H bonds that prone intramolecular atom transfer. protocol features broad compatibility, product diversity, exclusive stereoselectivity, thus providing practical strategy for elusive radical unactivated alkynes.

Language: 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, Journal Year: 2025, Volume and Issue: unknown, P. 5796 - 5805

Published: March 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.

Language: Английский

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Cascade cyclization of alkene-tethered acylsilanes and allylic sulfones enabled by unproductive energy transfer photocatalysis

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: Oct. 16, 2022

Abstract Developing photo-induced cascade cyclization of alkene-tethered acylsilanes is challenging, because are unstable under light irradiation. Herein, we report that the energy transfer from excited to a photocatalyst possesses lower triplet can inhibit undesired decomposition acylsilanes. With neutral Eosin Y as photocatalyst, an efficient synthesis cyclopentanol derivatives achieved with and allylic sulfones. The reaction shows broad substrate scope synthetic potential this transformation highlighted by construction which contain fused-ring or bridged-ring.

Language: Английский

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