Energy transfer photocatalysis: exciting modes of reactivity

Chemical Society Reviews, Год журнала: 2024, Номер 53(3), С. 1068 - 1089

Опубликована: Янв. 1, 2024

Leveraging light energy to expose the ‘dark’ reactive states describes whole essence of triplet–triplet transfer. This offers an impressive opportunity conduct a multitude diverse reactions and access sought-after molecular motifs.

Язык: Английский

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EnT-Mediated N–S Bond Homolysis of a Bifunctional Reagent Leading to Aliphatic Sulfonyl Fluorides

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(4), С. 2364 - 2374

Опубликована: Янв. 18, 2023

Sulfur(VI) fluoride exchange (SuFEx) gives rise to a plethora of high-valent sulfur linkages; however, the availability (aliphatic) sulfonyl manifolds lag behind, owing limited sources introducing SO2F moiety via classical two-electron approach. Recently, radical-based methodologies have emerged as complementary strategy increase diversity accessible click partners. In this work, synthesis bench-stable sulfamoyl reagent is presented, which may undergo sigma-bond homolysis upon visible-light-induced sensitization form protected β-amino fluorides from alkene feedstocks. Notably, offers an appealing access various building blocks for peptido fluorides, relevant in medicinal chemistry context, well intriguing entry β-ammonium sulfonates and β-sultams, alkenes. Densely functionalized 1,3-sultones were obtained by employing allyl alcohols substrates. Surprisingly, chloride-derived β-imino underwent S-O bond formation ring closure yield rigid cyclopropyl sulfonate ester under SuFEx conditions. Furthermore, engaging thiol-based hydrogen atom donor reaction, reactivity same can be tuned toward direct aliphatic fluorides. Mechanistic experiments indicate energy transfer (EnT)-mediated process. The transient radical adds product occurs either radical-radical coupling or (HAT), respectively.

Язык: Английский

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Metal-Free Amino(hetero)arylation and Aminosulfonylation of Alkenes Enabled by Photoinduced Energy Transfer

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(30), С. 16630 - 16641

Опубликована: Июль 24, 2023

β-(Hetero)arylethylamines are privileged structural motifs found in many high-value organic molecules, including pharmaceuticals and natural products. To construct these important molecular skeletons, previous methods mainly achieved by amino(hetero)arylation reaction with the aid of transition metals preactivated substrates. Herein, we report a metal-free photoinduced intermolecular for single-step installation both (hetero)aryl iminyl groups across alkenes an efficient regioselective manner. This method shows broad scope (up to 124 examples) excellent tolerance various olefins─from simplest ethylene complex multisubstituted can all participate reaction. Furthermore, aminosulfonylation be also conducted presence sodium bisulfite as SO2 source.

Язык: Английский

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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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Photoredox-Catalyzed Alkene Acylesterification with Acyloxime Esters via C–C and Tertiary C–O Bond Formation

Organic Letters, Год журнала: 2025, Номер unknown

Опубликована: Янв. 7, 2025

We describe an efficient acyl esterification method for alkenes utilizing acyloxime esters as bifunctional reagents featuring radical acylation and congested C–O bond formation. This approach is characterized by mild photoredox conditions, high step atom economy, a broad substrate scope, excellent regioselectivity. A variety of valuable α-acyl hindered alcohol esters, including those obtained via gram-scale synthesis late-stage functionalization pharmaceutical molecules, were presented, demonstrating its synthetic potential practicability.

Язык: Английский

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Metal-Free Photoinduced Acylboration of [1.1.1]Propellane via Energy Transfer Catalysis

ACS Catalysis, Год журнала: 2023, Номер 13(14), С. 9542 - 9549

Опубликована: Июль 5, 2023

Highly strained 1,3-disubstituted bicyclo[1.1.1]pentanes (BCPs) have been established as bioisosteres of para-disubstituted benzene because they impart valuable pharmacokinetic properties. Herein, we demonstrate an energy transfer-mediated protocol for acylboration [1.1.1]propellanes that allows the direct construction various carbonyl species, such carbamoyl-, carboxyl-, and acyl-, in tandem with synthetically versatile pinacol boronate (Bpin) groups onto BCP substructure under simple reaction conditions. Moreover, drug-like molecules containing boronates are further submitted to late-stage functionalization events. Several important transformations Bpin functional group boronates, including photoinduced cross-coupling reactions BCP-BF3K, derived from BCP-Bpin, were successfully performed showcase synthetic utility. Additionally, diverse elaborate mechanistic investigations provide insights, a plausible mechanism is proposed.

Язык: Английский

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Regiospecific Alkene Aminofunctionalization via an Electrogenerated Dielectrophile

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(15), С. 8299 - 8307

Опубликована: Апрель 6, 2023

Modular strategies to rapidly increase molecular complexity have proven immensely synthetically valuable. In principle, transformation of an alkene into a dielectrophile presents opportunity deliver two unique nucleophiles across alkene. Unfortunately, the selectivity profiles known dielectrophiles largely precluded this deceptively simple synthetic approach. Herein, we demonstrate that dicationic adducts generated through electrolysis alkenes and thianthrene possess profile relative more conventional dielectrophiles. Specifically, these species undergo single perfectly regioselective substitution reaction with phthalimide salts. This observation unlocks appealing new platform for aminofunctionalization reactions. As illustrative example, implement reactivity paradigm address longstanding challenge: diamination distinct nitrogen nucleophiles. Studies mechanism process reveal key alkenyl thianthrenium salt intermediate controls exquisite regioselectivity highlight importance proton sources in controlling sulfonium electrophiles.

Язык: Английский

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Metal-free photosensitized radical relay 1,4-carboimination across two distinct olefins

Chemical Science, Год журнала: 2023, Номер 14(9), С. 2447 - 2454

Опубликована: Янв. 1, 2023

Intermolecular carboamination of olefins offers a powerful platform for the rapid construction structurally complex amines from abundant feedstocks. However, these reactions often require transition-metal catalysis, and are mainly limited to 1,2-carboamination. Herein, we report novel radical relay 1,4-carboimination across two distinct with alkyl carboxylic acid-derived bifunctional oxime esters

Язык: Английский

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Photosensitized Vicinal Sulfonylamination of Alkenes with Oxime Ester and DABCO·(SO₂)₂

Organic Letters, Год журнала: 2023, Номер 25(10), С. 1782 - 1786

Опубликована: Март 8, 2023

A metal-free photosensitized three-component reaction of oxime esters, alkenes, and DABCO·(SO2)2 was developed. This protocol could accommodate a wide substrate scope, including activated unactivated alkenes aryl aliphatic carboxylic acid delivering broad range β-amino sulfones in moderate to high yields. The insertion SO2 as linker moiety allows the manipulation functionality process, expanding utility esters bifunctional reagents.

Язык: Английский

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