Energy transfer photocatalysis: exciting modes of reactivity

Chemical Society Reviews, Journal Year: 2024, Volume and Issue: 53(3), P. 1068 - 1089

Published: Jan. 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.

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

ACS Catalysis, Journal Year: 2025, Volume and Issue: 15(3), P. 1854 - 1941

Published: Jan. 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

Language: Английский

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Imidazophenothiazine-Based Thermally Activated Delayed Fluorescence Materials with Ultra-Long-Lived Excited States for Energy Transfer Photocatalysis

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(33), P. 18366 - 18381

Published: Aug. 9, 2023

Triplet-triplet energy transfer (EnT) is a powerful activation pathway in photocatalysis that unlocks new organic transformations and improves the sustainability of synthesis. Many current examples, however, still rely on platinum-group metal complexes as photosensitizers, with associated high costs environmental impacts. Photosensitizers exhibit thermally activated delayed fluorescence (TADF) are attractive fully alternatives EnT photocatalysis. However, TADF photocatalysts incorporating heavy atoms remain rare, despite their utility inducing efficient spin-orbit-coupling, intersystem-crossing, consequently triplet population. Here, we describe synthesis imidazo-phenothiazine (IPTZ), sulfur-containing heterocycle locked planar structure shallow LUMO level. This acceptor used to prepare seven TADF-active energies up 63.9 kcal mol-1. We show sulfur incorporation spin-orbit coupling increases lifetimes 3.64 ms, while also allowing for tuning photophysical properties via oxidation at atom. These IPTZ materials applied five seminal reactions: [2 + 2] cycloaddition, disulfide-ene reaction, Ni-mediated C-O C-N cross-coupling afford etherification, esterification, amination products, outcompeting industry-standard photocatalyst 2CzPN four studied scenarios. Detailed theoretical studies understand structure-activity relationships demonstrate key role atom effect design superior photocatalytic performance.

Language: Английский

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Photocatalytic 1,2-Iminosulfonylation and Remote 1,6-Iminosulfonylation of Olefins

Organic Letters, Journal Year: 2023, Volume and Issue: 25(10), P. 1742 - 1747

Published: March 8, 2023

A new class of iminosulfonylation reagents were developed and extensively used in the 1,2-iminosulfonylation various olefins. Olefins containing bioactive molecules, such as indomethacin, gemfibrozil, clofibrate, fenbufen, afforded desired products synthetically useful yields. Furthermore, first remote 1,6-iminosulfonylation alkenes was realized by using oxime ester bifunctionalization reagents. Overall, more than 40 structurally diverse β-imine sulfones obtained moderate to excellent

Language: Английский

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Three-Component Photochemical 1,2,5-Trifunctionalizations of Alkenes toward Densely Functionalized Lynchpins

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(43), P. 23814 - 23823

Published: Oct. 18, 2023

Radical remote 1,n-difunctionalization reactions (n > 2) of alkenes are powerful tools to efficiently introduce functional groups with selected distances into target molecules. Among these reactions, 1,5-difunctionalizations an important subclass, leading sought-after scaffolds, but typically suffer from tailored starting materials and strict limitations for the formed group in 2-position. Seeking address issues make radical more applicable, we report a novel three-component 1,2,5-trifunctionalization reaction between imine-based bifunctional reagents two distinct alkenes, driven by visible light energy transfer-catalysis. Key achieving this selective one-step installation three different via choreographed formation four bonds was utilization 1,2-boron shift rigorous capitalization polarities stabilities. Thorough mechanistic studies were carried out, synthetic utility obtained products demonstrated various downstream modifications. Notably, addition functionalization individual groups, their interplay gave rise unique array cyclic products.

Language: Английский

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Photocatalytic Unsymmetrical Diamination of Styrenes, Indoles, and Benzofurans Facilitated by Benzotriazolyl and Iminyl Radicals

Organic Letters, Journal Year: 2024, Volume and Issue: 26(2), P. 559 - 564

Published: Jan. 9, 2024

Utilizing energy transfer catalysis, this research employed the bifunctional reagents benzotriazole carboxylic acid oxime esters to simultaneously generate and imine radicals. The synthesis of two distinct C–N bonds in a single conversion is showcased through radical addition radical–radical cross-coupling processes between ester olefins. This process facilitates intermolecular two-component unsymmetrical diamination reaction Using approach, more than 40 benzotriazole-containing molecules were successfully synthesized using styrene, indole, benzofuran as acceptors, with yields ranging from moderate excellent.

Language: Английский

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Metal-free photosensitized aminosulfonylation of alkenes: a practical approach to β-amido sulfones

Green Chemistry, Journal Year: 2023, Volume and Issue: 25(10), P. 3857 - 3863

Published: Jan. 1, 2023

A general and environmentally friendly organic photo-induced strategy was developed for the synthesis of diverse alkyl-substituted β-amino sulfone derivatives, including primary, secondary, tertiary products.

Language: Английский

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Photoinduced Difunctionalization of Diazenes Enabled by N–N Radical Coupling

Organic Letters, Journal Year: 2023, Volume and Issue: 25(36), P. 6671 - 6676

Published: Aug. 29, 2023

In this study, a metal-free difunctionalization strategy for diazenes was developed using range of bifunctionalization reagents. This involves unique N(sp3)–N(sp2) radical coupling between the hydrazine and imine radical. More than 30 triazane core motifs were constructed by installing imines various functional groups, including alkyl, phenyl, cyanoalkyl, sulfonyl on both ends nitrogen–nitrogen bond in an efficient manner.

Language: Английский

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Photocatalytic vinyl radical-mediated multicomponent 1,4-/1,8-carboimination across alkynes and olefins/(hetero)arenes

Science China Chemistry, Journal Year: 2023, Volume and Issue: 67(2), P. 558 - 567

Published: Sept. 27, 2023

Language: Английский

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