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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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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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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Remote Radical 1,3-, 1,4-, 1,5-, 1,6- and 1,7-Difunctionalization Reactions

Molecules, Journal Year: 2023, Volume and Issue: 28(7), P. 3027 - 3027

Published: March 28, 2023

Radical transformations are powerful in organic synthesis for the construction of molecular scaffolds and introduction functional groups. In radical difunctionalization reactions, radicals first functionalized intermediates can be relocated through resonance, hydrogen atom or group transfer, ring opening. The resulting undertake following paths second functionalization: (1) couple with other groups, (2) oxidize to cations then react nucleophiles, (3) reduce anions electrophiles, (4) metal-complexes. rearrangements provide opportunity 1,3-, 1,4-, 1,5-, 1,6-, 1,7-difunctionalization products. Multiple ways initiate reaction coupling intermediate make reactions good at remote positions. These offer advantages synthetic efficiency, operation simplicity, product diversity.

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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Photosensitized 1,2-Difunctionalization of Alkenes to Access β-Amino Sulfonamides

Organic Letters, Journal Year: 2024, Volume and Issue: 26(10), P. 2108 - 2113

Published: March 5, 2024

A metal-free photosensitized 1,2-imino-sulfamoylation of olefins by employing a tailor-made sulfamoyl carbamate as the difunctionalization reagent has been established. This protocol exhibits versatility across broad substrate scope, including aryl and aliphatic alkenes, leading to synthesis diverse β-imino sulfonamides in moderate good yields. method is characterized its reaction system, mild conditions, excellent regioselectivity, high atom economy, serving promising platform for preparation β-amino sulfonamide-containing molecules, particularly context drug discovery.

Language: Английский

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Carbamoylarylation of Alkenes with N-Aryl Oxamic Acids Involving 1,4-Aryl Migration Via C(aryl)–N Bond Cleavage

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(8), P. 5972 - 5977

Published: April 4, 2024

We report carbamoylarylation of alkenes using N-aryl oxamic acid derivatives under visible-light irradiation. Reactions with carbamoyl radicals generated to afford Giese-type products or 3,4-dihydroquinolin-2(1H)-ones via ortho-radical addition an aryl amide moiety have been previously reported. However, this study reveals that the introduction a removable bulky group onto nitrogen atom acids facilitates radical alkenes, resulting in 1,4-aryl migration C(aryl)–N bond cleavage, thus affording arylpropanamides. Various such as acrylic and styrene derivatives, are successfully applied synthesis variety arylpropanamide including 1,4-dicarbonyl amides, forming two C–C bonds.

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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Photo-induced imino functionalizations of alkenes via intermolecular charge transfer

Chemical Science, Journal Year: 2023, Volume and Issue: 14(40), P. 11170 - 11179

Published: Jan. 1, 2023

A catalyst-free photosensitized strategy has been developed for regioselective imino functionalizations of alkenes via the formation an EDA complex. This photo-induced protocol facilitates construction structurally diverse β-imino sulfones and vinyl in moderate to high yields. Mechanistic studies reveal that reaction is initiated with intermolecular charge transfer between oximes sulfinates, followed by fragmentation generate a persistent iminyl radical transient sulfonyl radical. also features excellent regioselectivity, broad functional group tolerance mild conditions. The late stage functionalization natural product derived compounds total synthesis some bioactive molecules have demonstrated highlight utility this protocol. Meanwhile, compatibility different donors proved generality strategy.

Language: Английский

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Visible-Light-Promoted Intermolecular β-Acyl Difunctionalization of Alkenes via Oxidative Radical-Polar Crossover

Organic Letters, Journal Year: 2023, Volume and Issue: 25(45), P. 8067 - 8071

Published: Nov. 8, 2023

A visible-light-induced β-acyl difunctionalization of alkenes with acyl oxime esters and various nucleophiles was developed to achieve molecular complexity from readily available raw materials via oxidative radical-polar crossover. variety nucleophiles, including NH-sulfoximines, indoles, indazole, trimethoxybenzene, were all effectively applicable the sustainable reaction system. The novel synthetic strategy features mild conditions, a broad substrate scope (39 examples), easy scale-up, excellent regioselectivity.

Language: Английский

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