Catalysis of Organic Reactions through Halogen Bonding

ACS Catalysis, Journal Year: 2019, Volume and Issue: 9(10), P. 9622 - 9639

Published: Sept. 4, 2019

Halogen bonding, the noncovalent interaction based on electrophilic halogen substituents, features very interesting properties, as illustrated by numerous applications continuously emerging in recent years, and is now sometimes considered a hydrophobic soft analogue of well-known hydrogen bond. Conventionally studied both silico solid state, its solution-phase particularly for catalyzing organic transformations are currently under active investigation. Herein we present conceptual treatise latest developments this regard discuss challenges associated with advancement more practical catalytic halogen-bonding systems.

Language: Английский

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σ‐Hole Interactions in Catalysis

European Journal of Organic Chemistry, Journal Year: 2020, Volume and Issue: 2020(34), P. 5473 - 5487

Published: June 8, 2020

Noncovalent interactions like halogen, chalcogen, and pnictogen bonding are known for a very long time. During the last decade, these have found different applications in catalysis. These forces often called σ‐hole which can be explained by anisotropic distribution of electron density around atoms. In this MiniReview, we will present recent catalysis discuss experimental computational investigations to gain more insights into underlying mechanisms.

Language: Английский

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Recent Progress in Synthetic Applications of Hypervalent Iodine(III) Reagents

Chemical Reviews, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 13, 2024

Hypervalent iodine(III) compounds have found wide application in modern organic chemistry as environmentally friendly reagents and catalysts. iodine are commonly used synthetically important halogenations, oxidations, aminations, heterocyclizations, various oxidative functionalizations of substrates. Iodonium salts arylating reagents, while iodonium ylides imides excellent carbene nitrene precursors. Various derivatives benziodoxoles, such azidobenziodoxoles, trifluoromethylbenziodoxoles, alkynylbenziodoxoles, alkenylbenziodoxoles group transfer the presence transition metal catalysts, under metal-free conditions, or using photocatalysts photoirradiation conditions. Development hypervalent catalytic systems discovery highly enantioselective reactions chiral represent a particularly recent achievement field chemistry. Chemical transformations promoted by many cases unique cannot be performed any other common, non-iodine-based reagent. This review covers literature published mainly last 7-8 years, between 2016 2024.

Language: Английский

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Halogen, Chalcogen, Pnictogen, and Tetrel Bonding in Non‐Covalent Organocatalysis: An Update

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(31)

Published: May 11, 2024

The use of noncovalent interactions based on electrophilic halogen, chalcogen, pnictogen, or tetrel centers in organocatalysis has gained noticeable attention. Herein, we provide an overview the most important developments last years with a clear focus experimental studies and catalysts which act via such non-transient interactions.

Language: Английский

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A Bidentate Iodine(III)‐Based Halogen‐Bond Donor as a Powerful Organocatalyst**

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 60(10), P. 5069 - 5073

Published: Nov. 20, 2020

Abstract In contrast to iodine(I)‐based halogen bond donors, iodine(III)‐derived ones have only been used as Lewis acidic organocatalysts in a handful of examples, and all cases they acted monodentate fashion. Herein, we report the first application bidentate bis(iodolium) salt organocatalyst Michael nitro‐Michael addition reaction well Diels–Alder that had not activated by noncovalent before. cases, performance this XB donor distinctly surpassed one arguably currently strongest organocatalyst. Bidentate coordination substrate was corroborated structural analysis DFT calculations transition states. Overall, catalytic activity system approaches strong acids like BF 3 .

Language: Английский

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Mechanism and Origins of Chemo- and Stereoselectivities of Aryl Iodide-Catalyzed Asymmetric Difluorinations of β-Substituted Styrenes

Journal of the American Chemical Society, Journal Year: 2018, Volume and Issue: 140(45), P. 15206 - 15218

Published: Oct. 23, 2018

The mechanism of the aryl iodide-catalyzed asymmetric migratory geminal difluorination β-substituted styrenes (Banik et al. Science 2016, 353, 51) has been explored with density functional theory computations. computed consists (a) activation iodoarene difluoride (ArIF2), (b) enantiodetermining 1,2-fluoroiodination, (c) bridging phenonium ion formation via SN2 reductive displacement, and (d) regioselective fluoride addition. According to computational model, ArIF2 intermediate is stabilized through halogen−π interactions between electron-deficient iodine(III) center benzylic substituents at catalyst stereogenic centers. Interactions ester carbonyl groups (I(III)+···O) are not observed in unactivated complex, but do occur upon hydrogen-bonding external Brønsted acid (HF). 1,2-fluoroiodination occurs alkene complexation electrophilic, cationic I(III) followed by C–F bond anti forming C–I bond. bound olefin adopt a spiro arrangement favored transition structures nearly periplanar disfavored structures. Multiple attractive non-covalent interactions, including slipped π···π stacking, C–H···O, C–H···π found underlie high induction. chemoselectivity for 1,1-difluorination versus 1,2-difluorination controlled mainly (1) steric effect substituent on olefinic double (2) nucleophilicity oxygen substrate.

Language: Английский

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The Pauli Repulsion-Lowering Concept in Catalysis

Accounts of Chemical Research, Journal Year: 2021, Volume and Issue: 54(8), P. 1972 - 1981

Published: March 24, 2021

ConspectusOrganic chemistry has undoubtedly had a profound impact on humanity. Day in and day out, we find ourselves constantly surrounded by organic compounds. Pharmaceuticals, plastics, fuels, cosmetics, detergents, agrochemicals, to name few, are all synthesized reactions. Very often, these reactions require catalyst order proceed timely selective manner. Lewis acids organocatalysts commonly employed catalyze considered enhance the frontier molecular orbital (FMO) interactions. A vast number of textbooks primary literature sources suggest that binding acid or an iminium reactant (R1) stabilizes its LUMO leads smaller HOMO(R2)–LUMO(R1) energy gap with other (R2), thus resulting faster reaction. This forms basis for so-called LUMO-lowering catalysis concept. Despite simplicity popularity FMO theory, deficiencies have emerged over years, as consequence FMOs not being operative factor catalysis. is ultimately incomplete always catalyzed Our groups recently undertaken concerted effort generate unified framework rationalize predict chemical reactivity using causal model rooted quantum mechanics. In this Account, propose concept Pauli repulsion-lowering understand fundamental processes chemistry. findings emerge from state-of-the-art computational methods, namely, activation strain (ASM) conjunction quantitative Kohn–Sham theory (KS-MO) matching decomposition analysis (EDA). The substrate only stabilization but also induces significant reduction two-orbital, four-electron repulsion involving key orbitals both reactants. originates, textbook acid-catalyzed Diels–Alder reaction, polarizing occupied π dienophile away carbon atoms form new bonds diene. polarization reduces overlap diene constitutes ultimate physical responsible acceleration process compared analogous uncatalyzed We show mechanism generally applicable regardless type reaction (Diels–Alder Michael addition reactions) way bonded reactants (i.e., pure covalent dative weaker hydrogen halogen bonds). envisage insights emerging our will guide future experimental developments toward design more efficient catalytic transformations.

Language: Английский

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A Multistage Halogen Bond Catalyzed Strain-Release Glycosylation Unravels New Hedgehog Signaling Inhibitors

Journal of the American Chemical Society, Journal Year: 2019, Volume and Issue: 141(13), P. 5381 - 5391

Published: March 8, 2019

Halogen bonding (XB) has recently emerged as a promising noncovalent activation mode that can be employed in catalysis. However, methodologies utilizing XB remain rare, and the hydrogen-bonding (HB) catalysis congeners are more widespread comparison. Herein, we demonstrate remarkable case whereby employment of strain-release glycosylation generates O,N-glycosides excellent anomeric selectivity exceeding HB activation. Deeper investigation unraveled catalyst dependencies on multiple stages mechanism hitherto unknown XB-glycosyl acceptor We present proof concept to interrogate sp3-rich glycosidic chemical space for novel biological activity, by integrating XB-catalyzed construction compound collection, evaluating these analogues via cell-based phenotypic screens. show defines new class glycosides inhibit hedgehog signaling pathway through nonsmoothened action, opening opportunities combat acquired cancer resistance.

Language: Английский

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“Anti‐Electrostatic” Halogen Bonding

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 59(27), P. 11150 - 11157

Published: March 30, 2020

Abstract Halogen bonding is often described as being driven predominantly by electrostatics, and thus adducts between anionic halogen bond (XB) donors (halogen‐based Lewis acids) anions seem counterintuitive. Such “anti‐electrostatic” XBs have been predicted theoretically but for organic XB donors, there are currently no experimental examples except a few cases of self‐association. Reported herein the synthesis two negatively charged organoiodine derivatives that form anti‐electrostatic with anions. Even though electrostatic potential universally negative across surface both compounds, DFT calculations indicate kinetic stabilization their halide complexes in gas phase particularly solution. Experimentally, self‐association was observed solid‐state structures, resulting dimers, trimers, infinite chains. In addition, co‐crystals halides were obtained, representing first an donor different anion. The lengths all interactions 14–21 % shorter than sum van der Waals radii.

Language: Английский

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Visible-Light-Driven Halogen-Bond-Assisted Direct Synthesis of Heteroaryl Thioethers Using Transition-Metal-Free One-Pot C–I Bond Formation/C–S Cross-Coupling Reaction

The Journal of Organic Chemistry, Journal Year: 2021, Volume and Issue: 86(3), P. 2570 - 2581

Published: Jan. 25, 2021

An efficient protocol for the synthesis of thioether directly from heteroarenes has been developed in presence visible light a one-pot manner at room temperature. This method involves two sequential reactions single pot where formation iodinated heteroarene is followed by transition-metal-free C–S coupling reaction. A wide range and thiol partners (including aliphatic thiols) have used thioethers. NMR studies DFT calculations revealed halogen bond between thiolate anion (halogen acceptor) iodoheteroarene donor). bonded complex on photoexcitation facilitates electron transfer to

Language: Английский

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