Light-activated hypervalent iodine agents enable diverse aliphatic C–H functionalization

Nature Chemistry, Год журнала: 2025, Номер 17(3), С. 365 - 372

Опубликована: Фев. 24, 2025

Язык: Английский

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Strategies and Mechanisms of First-Row Transition Metal-Regulated Radical C–H Functionalization

Chemical Reviews, Год журнала: 2024, Номер 124(17), С. 10192 - 10280

Опубликована: Авг. 8, 2024

Radical C–H functionalization represents a useful means of streamlining synthetic routes by avoiding substrate preactivation and allowing access to target molecules in fewer steps. The first-row transition metals (Ti, V, Cr, Mn, Fe, Co, Ni, Cu) are Earth-abundant can be employed regulate radical functionalization. use such is desirable because the diverse interaction modes between metal complexes species including addition center, ligand complexes, substitution single-electron transfer radicals hydrogen atom noncovalent complexes. Such interactions could improve reactivity, diversity, selectivity transformations allow for more challenging reactions. This review examines achievements this promising area over past decade, with focus on state-of-the-art while also discussing existing limitations enormous potential high-value regulated these metals. aim provide reader detailed account strategies mechanisms associated

Язык: Английский

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Site‐Selective Distal C(sp3)–H Bromination of Aliphatic Amines as a Gateway for Forging Nitrogen‐Containing sp3 Architectures

Angewandte Chemie International Edition, Год журнала: 2024, Номер unknown

Опубликована: Май 21, 2024

Herein, we disclose a new strategy that rapidly and reliably incorporates bromine atoms at distal, secondary C(sp

Язык: Английский

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Manganese Catalyzed Oximation of Hydrocarbons to Oximes

Research Square (Research Square), Год журнала: 2025, Номер unknown

Опубликована: Фев. 26, 2025

Oximes are used in many scientific and industrial domains, ranging from organic synthesis through biotechnology to materials science. Traditionally, their necessitates the use of hydrocarbons with specific functional groups, such as carbonyls, which often more challenging expensive obtain compared non-functionalized counterparts. Here we introduce a new approach that enables direct oximes via oxidative oximation methylene C-H bonds — most prevalent molecular unit world molecules. Under catalysis manganese complex hydrogen peroxide oxidant hydroxylamine sulfate amine source, demonstrate diverse array molecules simple chemicals like propane cyclohexane compounds antimalarial drug artemisinin can be oximated at synthetically significant yields under mild conditions. The catalyst displays good level functionality tolerance predictable site selectivity molecule settings. Our opens avenues for oxime is anticipated have broad applications production fine commodity chemicals, bioactive molecules, materials.

Язык: Английский

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Turning the lifetime of the N-oxyl radicals for enhanced photocatalytic oxidation of C–H bonds via π-π interactions

Chemical Engineering Journal, Год журнала: 2025, Номер unknown, С. 162068 - 162068

Опубликована: Апрель 1, 2025

Язык: Английский

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Hexafluoroisopropanol Solvent Effects on Enantioselectivity of Dirhodium Tetracarboxylate-Catalyzed Cyclopropanation

Journal of the American Chemical Society, Год журнала: 2025, Номер unknown

Опубликована: Апрель 16, 2025

In recent years, additives that modulate both reactivity and selectivity in rhodium-catalyzed reactions of aryldiazoacetates have become increasingly prominent. 1,1,1,3,3,3-Hexafluoroisopropanol (HFIP) has been shown to a profound effect on rhodium carbene selectivity, especially enabling cyclopropanation the presence various nucleophilic poisons. HFIP also variable influence enantioselectivity catalyzed by chiral dirhodium tetracarboxylates, this study examines fundamental properties carbene/HFIP system through experimentation, density functional theory (DFT), molecular dynamics (MD) simulations. These studies revealed C4-symmetric bowl-shaped catalysts, which previously considered be relatively rigid, experience far greater flexibility hydrogen bonding media, resulting distortion catalysts. explain why even though majority catalysts drop HFIP, some such as Rh2(TCPTAD)4, lead switch enantioselectivity, whereas others, Rh2(NTTL)4, considerably enhanced enantioselectivity.

Язык: Английский

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Unveiling the Delicate Balance of Polarity and Strain Effect in Determining the Site-Selective Intramolecular Hydrogen Atom Transfers

The Journal of Physical Chemistry A, Год журнала: 2025, Номер unknown

Опубликована: Май 28, 2025

Abstracting hydrogen atoms from different non-activated C(sp3)-H bonds to generate various carbon radicals provides an efficient way further broaden the application of intramolecular atom transfer (HAT) reactions. This study thoroughly explores roles kinetic factors (polarity and strain effects) thermodynamic (bond dissociation energy) in affecting reactivity HAT reactions, contributing rational design suitable substrates. Furthermore, site-selectivity, as represented by barrier height difference (ΔΔG1, n-1, n'≠, where 1,n 1,n' denotes 1,n-HAT 1,n'-HAT reaction) correlates reasonably well with local electrophilicity index (ΔΔω1,n-1,n'loc), demonstrating vital role polarity achieving site-selective Additionally, effects are considered alongside polar explain observed products, offering fundamental insight into balancing these determining proper engaged reaction.

Язык: Английский

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tert‐Butyl as a Functional Group: Non‐Directed Catalytic Hydroxylation of Sterically Congested Primary C−H Bonds

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(28)

Опубликована: Май 1, 2024

Abstract The tert ‐butyl group is a common aliphatic motif extensively employed to implement steric congestion and conformational rigidity in organic organometallic molecules. Because of the combination high bond dissociation energy (~100 kcal mol −1 ) limited accessibility, absence directing groups, neither radical nor approaches are effective for chemical modification C−H bonds. Herein we overcome these limits by employing highly electrophilic manganese catalyst, [Mn( CF3 bpeb)(OTf) 2 ], that operates strong hydrogen donor solvent nonafluoro‐ alcohol (NFTBA) catalytically activates peroxide generate powerful manganese‐oxo species effectively oxidizes Leveraging on interplay steric, electronic, medium torsional effects, site‐selective product chemoselective hydroxylation accomplished with broad reaction scope, delivering primary alcohols as largely dominant products preparative yields. Late‐stage at sites demonstrated 6 densely functionalized molecules pharmaceutical interest. This work uncovers novel disconnection approach, harnessing potential functional strategic synthetic planning complex molecular architectures.

Язык: Английский

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Recent Advances and Prospects in Manganese‐Catalyzed C‐H Activation

Advanced Synthesis & Catalysis, Год журнала: 2024, Номер 366(19), С. 3963 - 3999

Опубликована: Авг. 6, 2024

Abstract C−H activation represents an interesting alternative to conventional cross‐coupling methods, avoiding the requirement of additional steps introduce activating groups. Generally, Pd‐catalyzed reactions have been extensively employed for activation. The high cost and limited availability resources Pd prompted us explore transition metals. In this context, researchers are turning Earth Abundant Metals (EAMs) like manganese iron their potential in Significant progress has made manganese‐catalysed recent years, showcasing excellent specificity, environmental compatibility, versatility across different substrates. This review summarises approximately 50 publications highlighting significant advancements field from 2020 2023.

Язык: Английский

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Enzymatic and Bio-inspired Enantioselective Oxidation of Non-activated C-H Bonds

Synthesis, Год журнала: 2024, Номер unknown

Опубликована: Авг. 26, 2024

Abstract The enantioselective oxidation of C–H bonds relies on two different approaches: the use enzymes or bio-inspired transition metal catalysts. Both are powerful tools, as they transform ubiquitous C(sp3)–H into valuable oxygenated building blocks. However, reaction remains a challenge in synthetic chemistry, continuously demanding efficient catalytic systems to improve substrate scopes. Optimization site- and enantioselectivities bio-catalytic is underpinned by protein engineering, while ligand design medium effects play crucial roles complexes. In this Short Review, recent advances field described, focusing reactions that target strong, non-activated bonds. 1 Introduction 1.1 Enantioselective Catalytic Oxidation Nature Bio-Inspired Systems 1.2 Biological Mechanism Challenges for Implementation Chirality with Synthetic Catalysts 1.3 Bio-Catalytic Systems: From Microorganism Engineered Enzymes 1.4 Mimicking Nature: Approach 1.5 Origin Enantioselectivity 2 Non-Activated Bonds 2.1 Hydroxylation at 2.2 Lactonization Enzymatic 2.3 2.4 Small-Molecule 3 Conclusions

Язык: Английский

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