γ-Amino Alcohols via Energy Transfer Enabled Brook Rearrangement

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(15), С. 10899 - 10907

Опубликована: Апрель 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.

Язык: Английский

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Visible-Light-Induced Energy-Transfer-Mediated Hydrofunctionalization and Difunctionalization of Unsaturated Compounds via Sigma-Bond Homolysis of Energy-Transfer Acceptors

ACS Catalysis, Год журнала: 2025, Номер 15(3), С. 1854 - 1941

Опубликована: Янв. 17, 2025

Over the past decade, visible-light-mediated energy-transfer (EnT) catalysis, particularly triplet–triplet (TTEnT) has emerged as a mild and environmentally friendly approach for diverse organic synthetic transformations. In contrast to photoredox which typically requires sacrificial electron donors or acceptors complete catalytic cycle, EnT photocatalysis generally proceeds with high atom economy while minimizing generation of wasteful byproducts. Furthermore, successful catalysis is contingent upon precise control redox potentials both photocatalysts substrates, strategies are primarily influenced by triplet energy compatibility between these entities. Considering growing importance photocatalysis, well hydrofunctionalization difunctionalization reactions in synthesis, this review systematically summarizes significant advancements EnT-enabled unsaturated compounds via sigma-bond homolysis over decade. Special emphasis placed on elucidating substrate scopes mechanistic scenarios. Additionally, discusses versatile applications methodologies addresses current challenges opportunities within evolving research field. This structured into six main categories based different types sigma-bonds undergoing homolysis. These include transformations mediated 1) N–O bond oxime esters other N,O-radical precursors; 2) N–S N-sulfonyl imines N,S-radical 3) chalcogen–chalcogen disulfides oxy/thio/selenosulfonates; 4) C–S tri/difluoromethylated sulfinates, acetylenic triflones, arylsulfonium salts; 5) C–X (X = halogen) halides; 6) acceptors. Through providing theoretical backgrounds along comprehensive overview currently employed acceptors, photosensitizers, contemporary EnT-induced compounds, aims serve an invaluable resource future innovations rapidly

Язык: Английский

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PolyBorylated Alkenes as Energy‐Transfer Reactive Groups: Access to Multi‐Borylated Cyclobutanes Combined with Hydrogen Atom Transfer Event

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(25)

Опубликована: Апрель 11, 2024

Abstract While polyborylated alkenes are being recognized for their elevated status as highly valuable reagents in modern organic synthesis, allowing efficient access to a diverse array of transformations, including the formation C−C and C‐heteroatom bonds, potential energy‐transfer reactive groups has remained unexplored. Yet, this holds key generating elusive biradical species, which can be captured by olefins, thereby leading construction new highly‐borylated scaffolds. Herein, we report designed strategy photosensitized [2+2]‐cycloadditions poly‐borylated with various olefins enabling regioselective synthesis cyclobutane motifs, 1,1‐di‐, 1,1,2‐tri‐, 1,1,2,2‐tetra‐borylated cyclobutanes. In fact, these compounds belong family that presently lacks synthetic pathways. Interestingly, when α‐methylstyrene was used, reaction involves an interesting 1,5‐hydrogen atom transfer (HAT). Mechanistic deuterium‐labeling studies have provided insight into outcome process. addition, cyclobutanes then demonstrated useful selective oxidation processes resulting cyclobutanones γ‐lactones.

Язык: Английский

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Revealing the nature of covalently tethered distonic radical anions in the generation of heteroatom-centered radicals: evidence for the polarity-matching PCET pathway

Chemical Science, Год журнала: 2024, Номер 15(31), С. 12398 - 12409

Опубликована: Янв. 1, 2024

The philicity-regulation and PCET mechanism of tether-tunable distonic radical anion-mediated generation heteroatom-centered radicals has been explored via experimental theoretical investigations.

Язык: Английский

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Atomic Carbon Equivalent: Design and Application to Diversity-Generating Skeletal Editing from Indoles to 3-Functionalized Quinolines

ACS Catalysis, Год журнала: 2024, Номер 14(17), С. 13343 - 13351

Опубликована: Авг. 22, 2024

Atomic carbon and its corresponding masked analogues are exceedingly underexplored intermediates in synthesis. Despite this, these reagents possess inimitable reactivity such as the ability to directly insert atoms into aromatic frameworks while simultaneously generating an additional bond at center further diversify structure. Herein, we report design of orthogonally reactive atomic equivalent Cl-DADO demonstrate application molecular editing indole pyrrole, accessing linchpin-containing ring-expanded heterocycles that can be subsequently derivatized. The value this approach broad applicability reagent highlighted by late-stage skeletal numerous natural products drug molecules.

Язык: Английский

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N -Heterocyclic carbene catalytic 1,2-boron migrative acylation accelerated by photocatalysis

Science Advances, Год журнала: 2024, Номер 10(30)

Опубликована: Июль 24, 2024

The transformation of organoboron compounds plays an important role in synthetic chemistry, and recent advancements boron-migration reactions have garnered considerable attention. Here, we report unprecedented 1,2-boron migrative acylation upon photocatalysis-facilitated

Язык: Английский

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Photoredox-Catalyzed Strain-Release-Driven Synthesis of Functionalized Spirocyclobutyl Oxindoles

Organic Letters, Год журнала: 2024, Номер 26(30), С. 6396 - 6401

Опубликована: Июль 24, 2024

Spirocyclobutyl oxindoles have garnered substantial attention in drug discovery and pharmaceuticals owing to their wide range of biological activities. Strain-release small-ring compounds is a powerful strategy enable efficient access complex molecules. In this study, we successfully realized photoredox-catalyzed strain-release radical spirocyclization approach attain functionalized spirocyclobutyl oxindoles. A diverse array radicals, such as sulfonyl, phosphonyl, trifluoromethyl, were added efficiently the strained C-C σ-bond bicyclobutanes (BCBs) afford library Furthermore, obtained products could be transformed into valuable building blocks. The observed reactivity selectivity been rationalized based on density functional theory calculations.

Язык: Английский

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Chemodivergent dearomatization of benzene-linked O-oxime esters via EnT-induced radical cross-coupling

Chemical Science, Год журнала: 2025, Номер unknown

Опубликована: Янв. 1, 2025

Radical-mediated dearomatization strategies offer a blueprint for building value-added and synthetically valuable three-dimensional skeletons from readily available aromatic starting materials.

Язык: Английский

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Cyclic Bifunctional Reagents Enabling a Strain-Release-Driven Formal [3 + 2] Cycloaddition of 2H-Azirines by Cascade Energy Transfer

Journal of the American Chemical Society, Год журнала: 2025, Номер unknown

Опубликована: Апрель 10, 2025

The energy transfer (EnT)-catalyzed ring opening and further decarboxylation of isoxazole-5(4H)-ones enables the in situ generation strained 2H-azirines. Subsequent selective C(sp2)-C(sp3) bond cleavage azirine intermediate allows a formal [3 + 2] cycloaddition with wide range electrophiles, unlocking access to valuable pyrroline-type moieties. Mechanistic experiments combination density functional theory (DFT) calculations revealed unique nature EnT-cascade process for three-membered aza-cycle while providing insight into regio- diastereoselectivity annulation. This mild straightforward method ensures rapid construction highly substituted cyclic imines, which can be easily converted pyrrolidines, fused oxaziridines, biologically relevant β-amino acid precursors.

Язык: Английский

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A Mechanistic Perspective on Photocatalytic EnT-Enabled C3-N-Heteroarylation of Aryl Quinoxaline via C(sp²)–C(sp²) Coupling

Organic Letters, Год журнала: 2025, Номер unknown

Опубликована: Апрель 11, 2025

An EnT-mediated C3-N-heteroarylation of 2-aryl quinoxalines via decarboxylative radical-radical cross-coupling (C(sp2)-C(sp2)) with oxime esters is presented. Upon photoactivation, the triplet energy photocatalyst transferred to both reacting partners (oxime ester and 2-phenylquinoxaline). The excited undergoes fragmentation a C-centered N-heteroaryl radical an N-centered imine radical. former attacks C3 site quinoxaline diradical, while latter acts as hydrogen atom abstractor (HAA). Computational studies revealed that C-C bond formation heteroaryl energetically more favorable than C-N formation.

Язык: Английский

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