Enantioselective [2π + 2σ] Cycloadditions of Bicyclo[1.1.0]butanes with Vinylazaarenes through Asymmetric Photoredox Catalysis

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(12), P. 8372 - 8380

Published: March 18, 2024

Here we present a highly enantioselective [2π + 2σ] photocycloaddition of bicyclo[1.1.0]butanes (BCBs). The reaction uses variety vinylazaarenes as partners and is catalyzed by polycyclic aromatic hydrocarbon (PAH)-containing chiral phosphoric acid bifunctional photosensitizer. A wide array pharmaceutically important bicyclo[2.1.1]hexane (BCH) derivatives have been synthesized with high yields, enantioselectivity, diastereoselectivity. In addition to the diverse 1-ketocarbonyl-3-substituted BCBs, α/β-substituted are compatible such an unprecedented photoredox catalytic pathway, resulting in successful assembly all-carbon quaternary stereocenter or two adjacent tertiary stereocenters on product.

Language: Английский

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Merging Photoinduced Electron Transfer with Hydrogen Atom Transfer: Formal β-C(sp³)–H Pyridination of Carbonyls

The Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 9, 2025

In this study, a novel approach that combines photoinduced electron transfer (ET) with hydrogen atom (HAT) has been introduced for the selective β-C(sp3)–H pyridination of carbonyl compounds. This method is notable its absence transition metals and ability to function under benign reaction conditions, resulting in range pyridinated derivatives consistently moderate good yields. The significance technique further underscored by potential late-stage functionalization pharmaceutically significant molecules. Mechanistic investigations confirmed proceeds via radical-mediated pathway.

Language: Английский

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Enantioselective Alkyl–Acyl Radical Cross-Coupling Enabled by Metallaphotoredox Catalysis

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 19, 2025

Radical-radical cross-coupling (RCC) offers a promising approach for carbon-carbon bond formation in organic synthesis, particularly creating complex, three-dimensional molecules. However, achieving both cross- and enantioselectivity RCC reactions has remained significant challenge. Here, we report novel metallaphotoredox platform that enables highly enantioselective decarboxylative coupling of carboxylic acid derivatives with aldehydes. Our strategy leverages independent control over radical generation subsequent through fine-tuning common photocatalyst simple chiral bis(oxazoline) nickel catalyst. This redox-neutral protocol requires no exogenous oxidants or reductants demonstrates broad substrate scope functional group compatibility the synthesis enantioenriched α-aryl α-amino ketones. The ketone products can be readily transformed into valuable β-amino alcohols, streamlining access to these important motifs. Furthermore, showcase potential this more challenging C(sp3)-C(sp3) alkyl-alkyl reactions. unified alkyl-acyl represents advance asymmetric catalysis underscores exploit new mechanisms solve long-standing synthetic problems.

Language: Английский

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Light-Driven Cobalt Hydride Catalyzed Hydroarylation of Styrenes

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(24), P. 14806 - 14811

Published: Nov. 22, 2022

We report a conceptually distinct strategy for the synthesis of 1,1-diarylalkanes and triarylalkanes. Key to this approach is use light simultaneously trigger (i) formation CoIII–H species which undergoes H atom transfer (MHAT) styrenes, giving carbon-centered radical, (ii) generation persistent (hetero)arene radical. Selective coupling these two yields Markovnikov hydroarylation products under mild conditions without precious metals. In contrast many previous approaches, electron-deficient partners are favored it possible construct highly congested quaternary centers, including those with three different aryl groups.

Language: Английский

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The green chemistry paradigm in modern organic synthesis

Russian Chemical Reviews, Journal Year: 2023, Volume and Issue: 92(12), P. RCR5104 - RCR5104

Published: Dec. 1, 2023

After the appearance of green chemistry concept, which was introduced in vocabulary early 1990s, its main statements have been continuously developed and modified. Currently, there are 10–12 cornerstones that should form basis for an ideal chemical process. This review analyzes accumulated experience achievements towards design products processes reduce or eliminate use generation hazardous substances. The presents views leading Russian scientists specializing various fields this subject, including homogeneous heterogeneous catalysis, fine basic organic synthesis, electrochemistry, polymer chemistry, based on bio-renewable feedstocks energetic compounds materials. A new approach to quantitative evaluation environmental friendliness by authors is described. <br> bibliography includes 1761.

Language: Английский

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Regio- and Stereoselective Reductive Coupling of Alkynes and Crotononitrile

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(50), P. 23001 - 23009

Published: Dec. 8, 2022

A new regio- and stereoselective reductive coupling of alkynes crotononitrile has been developed via visible light organophotoredox cobalt dual catalysis. variety enantioenriched homoallylic nitriles bearing a stereodefined trisubstituted alkene have easily synthesized with good to excellent (up >20:1 rr), stereo- (>20:1 E/Z), enantioselectivity 98% ee) control under mild conditions. The corresponding nitrile products were smoothly converted into various chiral building blocks. Remarkably, simple organic base together water utilized as hydrogen sources in this photoinduced reaction.

Language: Английский

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Enantioselective Chemodivergent Three-Component Radical Tandem Reactions through Asymmetric Photoredox Catalysis

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(36), P. 20141 - 20148

Published: Aug. 28, 2023

Chemodivergent synthesis has been achieved in asymmetric photocatalysis. Under a dual catalyst system consisting of chiral phosphoric acid and DPZ as photosensitizer, different inorganic bases enabled the formation two sets valuable products from three-component radical tandem transformations 2-bromo-1-arylenthan-1-ones, styrenes, quinoxalin-2(1H)-ones. The key to success was distinct pKa environment, which radicals that formed on quinoxalin-2(1H)-one rings after addition processes underwent either single-electron oxidation or reduction. In addition, this work represents first use quinoxalin-2(1H)-ones photoredox catalysis.

Language: Английский

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Catalytic Asymmetric Hydrophosphinylation of 2‐Vinylazaarenes to Access P‐Chiral 2‐Azaaryl‐Ethylphosphine Oxides

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(16)

Published: Feb. 22, 2023

A chiral Brønsted acid-catalysed asymmetric hydrophosphinylation of 2-vinylazaarenes by secondary phosphine oxides is described. variety P-chiral 2-azaaryl-ethylphosphine are synthesized with high yields and ees, which both the substituents phosphines azaarenes can be flexibly modulated, underscoring an exceptionally broad scope substrates. These adducts valuable to metal catalysis since resultant tertiary from reduction them verified as a kind effective C1 -symmetric 1,5-hybrid P,N-ligands. Importantly, this platform enables generic efficient kinetic resolution oxides. It thus provides expedient approach access enantiomers derived hydrophosphinylation, further improving utility method.

Language: Английский

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Recent Advances in C–H Functionalisation through Indirect Hydrogen Atom Transfer

Molecules, Journal Year: 2023, Volume and Issue: 28(16), P. 6127 - 6127

Published: Aug. 18, 2023

The functionalisation of C–H bonds has been an enormous achievement in synthetic methodology, enabling new retrosynthetic disconnections and affording simple equivalents for synthons. Hydrogen atom transfer (HAT) is a key method forming alkyl radicals from substrates. Classic reactions, including the Barton nitrite ester reaction Hofmann–Löffler–Freytag reaction, among others, provided early examples HAT. However, recent developments photoredox catalysis electrochemistry have made HAT powerful tool capable introducing wide range functional groups into bonds. Moreover, greater mechanistic insights stimulated development increasingly site-selective protocols. Site-selectivity can be achieved through tuning electron density at certain using additives, judicious choice reagent, solvent system. Herein, we describe latest methods functionalizing C–H/Si–H/Ge–H indirect between 2018–2023, as well critical discussion reagents, aspects, substrate scopes, background contexts

Language: Английский

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Photocatalyst-free, metal-free, visible light-induced thiolation/pyridylation of styrenes using an electron donor–acceptor complex as a bifunctional reagent

Organic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 10(5), P. 1166 - 1172

Published: Jan. 1, 2023

Visible light-induced intermolecular thiolation/pyridylation of styrenes using a thiolate-based EDA complex as bifunctional reagent under mild conditions free photocatalyst, metal or external redox agent is reported.

Language: Английский

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