Visible Light-Induced Reactions of Diazo Compounds and Their Precursors

Chemical Reviews, Journal Year: 2024, Volume and Issue: 124(11), P. 7214 - 7261

Published: May 16, 2024

In recent years, visible light-induced reactions of diazo compounds have attracted increasing attention in organic synthesis, leading to improvement existing reactions, as well the discovery unprecedented transformations. Thus, photochemical or photocatalytic generation both carbenes and radicals provide milder tools toward these key intermediates for many valuable However, vast majority transformations represent new reactivity modes compounds, which are achieved by decomposition photoredox catalysis. particular, use a redox-active photocatalysts opens avenue plethora radical reactions. The application methods led inaccessible classical associated with metal carbenes. most cases, act sources but can also serve acceptors. Importantly, described processes operate under mild, practical conditions. This Review describes this subfield compound chemistry, particularly focusing on advancements.

Language: Английский

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Advances in heterocycle synthesis through photochemical carbene transfer reactions

Chemical Communications, Journal Year: 2024, Volume and Issue: 60(16), P. 2125 - 2136

Published: Jan. 1, 2024

In this feature article, we focus on the photochemical strategy for construction of heterocyclic skeletons, specifically highlighting methods that employ visible light-promoted carbene transfer reactions.

Language: Английский

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Cu-Catalyzed Diastereo- and Enantioselective Synthesis of Borylated Cyclopropanes with Three Contiguous Stereocenters

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

Published: Jan. 17, 2025

Direct synthesis of enantioenriched scaffolds with multiple adjacent stereocenters remains an important yet challenging task. Herein, we describe a highly diastereo- and enantioselective Cu-catalyzed alkylboration cyclopropenes, less reactive alkyl iodides as electrophiles, for the efficient tetra-substituted borylated cyclopropanes bearing three consecutive stereocenters. This protocol features mild conditions, broad substrate scope, good functional group tolerance, affording array chiral in to high yields excellent enantioselectivities. Detailed mechanistic experiments kinetic studies were conducted elucidate reaction pathway rate-determining step reaction. DFT calculations revealed that π···π stacking interaction between phenyl groups on phosphorus ligand, along smaller distortion CuL-Bpin part, contributed The synthetic utility was showcased by facile some valuable centers.

Language: Английский

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Photosensitized O ₂ enables intermolecular alkene cyclopropanation by active methylene compounds

Science, Journal Year: 2023, Volume and Issue: 381(6657), P. 545 - 553

Published: Aug. 3, 2023

Cyclopropanes are key features in many preclinical, clinical, and commercial drugs, as well natural products. The most prolific technique for their synthesis is the metal-catalyzed reaction of an alkene with a diazoalkane, highly energetic reagent requiring stringent safety precautions. Discovery alternative innocuous reagents remains ongoing challenge. Herein, we report simple photoredox-catalyzed intermolecular cyclopropanation unactivated alkenes active methylene compounds. proceeds neutral solvent under air or dioxygen (O 2 ) photoredox catalyst excited by blue light-emitting diode light iodine co-catalyst that either added molecular generated situ from alkyl iodides. Mechanistic investigations indicate photosensitized O plays vital role generation carbon-centered radicals both addition compounds to ring closure.

Language: Английский

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Vitamin B₁₂‐Photocatalyzed Cyclopropanation of Electron‐Deficient Alkenes Using Dichloromethane as the Methylene Source**

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 63(2)

Published: Nov. 28, 2023

Abstract The cyclopropyl group is of great importance in medicinal chemistry, as it can be leveraged to influence a range pharmaceutical properties drug molecules. This report describes Vitamin B 12 ‐photocatalyzed approach for the cyclopropanation electron‐deficient alkenes using dichloromethane (CH 2 Cl ) methylene source. reaction proceeds good excellent yields under mild conditions, has functional compatibility, and highly chemoselective. scope could also extended preparation D ‐cyclopropyl methyl‐substituted adducts starting from CD 1,1‐dichloroethane, respectively.

Language: Английский

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Diastereoselective Synthesis of Cyclopropanes from Carbon Pronucleophiles and Alkenes

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(21)

Published: March 16, 2023

Abstract Cyclopropanes are desirable structural motifs with valuable applications in drug discovery and beyond. Established alkene cyclopropanation methods give rise to cyclopropanes a limited array of substituents, difficult scale, or both. Herein, we disclose new cyclopropane synthesis through the formal coupling abundant carbon pronucleophiles unactivated alkenes. This strategy exploits dicationic adducts derived from electrolysis thianthrene presence substrates. We find that these dielectrophiles undergo methylene via alkenyl thianthrenium intermediates. protocol is scalable, proceeds high diastereoselectivity, tolerates diverse functional groups on both pronucleophile partners. To validate utility this procedure, prepared an substituted analogs established en route multiple pharmaceuticals.

Language: Английский

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Photocatalytic Synthesis of Indanone, Pyrone, and Pyridinone Derivatives with Diazo Compounds as Radical Precursors

Organic Letters, Journal Year: 2024, Volume and Issue: 26(7), P. 1393 - 1398

Published: Feb. 12, 2024

We disclose herein a photocatalytic radical cascade cyclization of diazoalkanes for the divergent synthesis important carbocycles and heterocycles. Under optimal reaction conditions, various indanone, pyrone, pyridinone derivatives can be obtained in moderate to good yields. Mechanistic experiments support formation carbon-centered radicals from through proton-coupled electron transfer process. Scale-up using continuous flow technology useful downstream application formed heterocycles further render strategy attractive valuable.

Language: Английский

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Modern Cyclopropanation via Non‐Traditional Building Blocks

ChemCatChem, Journal Year: 2024, Volume and Issue: 16(14)

Published: March 13, 2024

Abstract Small, strained carbocyclic systems have fascinated organic chemists from both a theoretical and synthetic standpoint. These often challenge conventional wisdom when it comes to molecular structure tactics for chemical construction. The cyclopropyl motif is one such ring system that remains at the forefront of method development in modern era. With advent an array non‐traditional building blocks, range new cyclopropanation processes using one‐ two‐electron strategies been developed not only overcome shortcomings classical approaches but also provide entry into wide classes cyclopropanes. This review discusses recent advances this area with emphasis on their mechanistic underpinnings potential applications. Additionally, concise overview properties traditional cyclopropanes provided.

Language: Английский

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Redox Approaches to Carbene Generation in Catalytic Cyclopropanation Reactions

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(29)

Published: May 16, 2024

Abstract Transition metal‐catalyzed carbene transfer reactions have a century‐old history in organic chemistry and are primary method for the synthesis of cyclopropanes. Much work this field has focused on use diazo compounds related precursors, which can fragment to catalyst with concomitant loss stable byproduct. Despite utility approach, there persistent limitations scope viable carbenes, most notably those lacking stabilizing substituents. By coupling two‐electron redox cycles, it is possible expand available starting materials that be used as precursors. In Minireview, we discuss emerging catalytic reductive cyclopropanation using either gem ‐dihaloalkanes or carbonyl compounds. This strategy inspired by classic stoichiometric transformations, such Simmons–Smith Clemmensen reduction, but instead entails formation catalytically generated transition metal carbenoid. We also present recent efforts generate carbenes directly from methylene (CR 2 H ) groups via formal 1,1‐dehydrogenation. These currently restricted substrates containing electron‐withdrawing substituents, serve facilitate deprotonation subsequent oxidation anion.

Language: Английский

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Emerging progress: photochemical transformation of nitroso compounds

Science China Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: July 17, 2024

Language: Английский

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