Recognition in the Domain of Molecular Chirality: From Noncovalent Interactions to Separation of Enantiomers

Chemical Reviews, Год журнала: 2022, Номер 122(16), С. 13235 - 13400

Опубликована: Авг. 2, 2022

It is not a coincidence that both chirality and noncovalent interactions are ubiquitous in nature synthetic molecular systems. Noncovalent interactivity between chiral molecules underlies enantioselective recognition as fundamental phenomenon regulating life human activities. Thus, represent the narrative thread of fascinating story which goes across several disciplines medical, chemical, physical, biological, other natural sciences. This review has been conceived with awareness modern attitude toward its consequences needs to be founded on multidisciplinary approaches disclose basis essential phenomena domain With primary aim discussing this topic an integrated way, comprehensive pool rational systematic information provided, concerns fundamentals chirality, description interactions, their implications processes occurring different contexts. A specific focus devoted enantioselection chromatography electromigration techniques because unique feature "multistep" processes. second motivation for writing make clear statement about state art, tools we have at our disposal, what still missing fully understand mechanisms underlying recognition.

Язык: Английский

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Bismuth Redox Catalysis: An Emerging Main-Group Platform for Organic Synthesis

ACS Catalysis, Год журнала: 2022, Номер 12(2), С. 1382 - 1393

Опубликована: Янв. 7, 2022

Bismuth has recently been shown to be able maneuver between different oxidation states, enabling access unique redox cycles that can harnessed in the context of organic synthesis. Indeed, various catalytic Bi platforms have discovered and revealed emerging opportunities field main group catalysis. The goal this perspective is provide an overview synthetic methodologies developed date, which capitalize on cycling. Recent methods via low-valent Bi(II)/Bi(III), Bi(I)/Bi(III), high-valent Bi(III)/Bi(V) couples are covered as well their underlying mechanisms key intermediates. In addition, we illustrate design strategies stabilizing bismuth species, highlight characteristic reactivity complexes, compared lighter p-block d-block elements. Although it not catalysis nature, also discuss a recent example non-Lewis acid, redox-neutral Bi(III) proceeding through organometallic steps. We close by discussing future directions hope Perspective will chemists with guiding principles for development transformations employing bismuth.

Язык: Английский

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Bismuth radical catalysis in the activation and coupling of redox-active electrophiles

Nature Chemistry, Год журнала: 2023, Номер 15(8), С. 1138 - 1145

Опубликована: Июнь 1, 2023

Radical cross-coupling reactions represent a revolutionary tool to make C(sp3)-C and C(sp3)-heteroatom bonds by means of transition metals photoredox or electrochemical approaches. However, the use main-group elements harness this type reactivity has been little explored. Here we show how low-valency bismuth complex is able undergo one-electron oxidative addition with redox-active alkyl-radical precursors, mimicking behaviour first-row metals. This paradigm for gives rise well-defined complexes, which could be fully characterized in solution solid state. The resulting Bi(III)-C(sp3) intermediates display divergent patterns depending on α-substituents alkyl fragment. Mechanistic investigations led development bismuth-catalysed C(sp3)-N reaction that operates under mild conditions accommodates synthetically relevant NH-heterocycles as coupling partners.

Язык: Английский

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Catalytic Hydrodefluorination via Oxidative Addition, Ligand Metathesis, and Reductive Elimination at Bi(I)/Bi(III) Centers

Journal of the American Chemical Society, Год журнала: 2021, Номер 143(32), С. 12487 - 12493

Опубликована: Авг. 6, 2021

Herein, we report a hydrodefluorination reaction of polyfluoroarenes catalyzed by bismuthinidenes, Phebox-Bi(I) and OMe-Phebox-Bi(I). Mechanistic studies on the elementary steps support Bi(I)/Bi(III) redox cycle that comprises C(sp2)–F oxidative addition, F/H ligand metathesis, C(sp2)–H reductive elimination. Isolation characterization cationic Phebox-Bi(III)(4-tetrafluoropyridyl) triflate manifests feasible addition into bond. Spectroscopic evidence was provided for formation transient hydride during catalysis, which decomposes at low temperature to afford corresponding bond while regenerating propagating Phebox-Bi(I). This protocol represents distinct catalytic example where main-group center performs three organometallic in low-valent manifold.

Язык: Английский

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Redox-Neutral Organometallic Elementary Steps at Bismuth: Catalytic Synthesis of Aryl Sulfonyl Fluorides

Journal of the American Chemical Society, Год журнала: 2021, Номер 143(51), С. 21497 - 21502

Опубликована: Дек. 16, 2021

A Bi-catalyzed synthesis of sulfonyl fluorides from the corresponding (hetero)aryl boronic acids is presented. We demonstrate that organobismuth(III) catalysts bearing a bis-aryl sulfone ligand backbone revolve through different canonical organometallic steps within catalytic cycle without modifying oxidation state. All have been validated, including insertion SO2 into Bi-C bonds, leading to structurally unique O-bound bismuth sulfinate complex. The protocol affords excellent yields for wide range aryl and heteroaryl acids, displaying functional group tolerance.

Язык: Английский

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Molecular bismuth(iii) monocations: structure, bonding, reactivity, and catalysis

Chemical Communications, Год журнала: 2021, Номер 57(37), С. 4483 - 4495

Опубликована: Янв. 1, 2021

Structurally defined, molecular bismuth(iii) cations show remarkable properties in coordination chemistry, Lewis acidity, and redox allowing for unique applications synthetic chemistry.

Язык: Английский

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Catalysis with Diboron(4)/Pyridine: Application to the Broad-Scope [3 + 2] Cycloaddition of Cyclopropanes and Alkenes

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(19), С. 8870 - 8882

Опубликована: Май 9, 2022

In contrast to the extensive but non-recyclable use of tetraalkoxydiboron(4) compounds as stoichiometric reagents in diverse reactions, this article reports an atom-economical reaction using a commercial diboron(4) catalyst. The key success was designing catalytic cycle for radical [3 + 2] cycloaddition involving pyridine cocatalyst generate from catalyst and reversibly mediate transfer boronyl radicals. comparison with known transition metal-based catalysts, current features not only metal-free conditions, inexpensive stable simple operation also remarkably broadened substrate scope. particular, previously unusable cyclopropyl ketones without activating group and/or alkenes 1,2-disubstitution 1,1,2-trisubstitution patterns were successfully used first time. Consequently, challenging cyclopentane various levels substitution (65 examples, 57 new products, up six substituents at all five ring atoms) readily prepared generally high excellent yield diastereoselectivity. applied concise formal synthesis anti-obesity drug building natural product-like complex bridged or spirocyclic compounds. Mechanistic experiments computational investigation support proposed relay catalysis featuring pyridine-assisted Overall, work demonstrates approach catalysts may lead development new, green, efficient metal-like boron-catalyzed organic reactions.

Язык: Английский

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Tandem C/N-Difunctionalization of Nitroarenes: Reductive Amination and Annulation by a Ring Expansion/Contraction Sequence

Journal of the American Chemical Society, Год журнала: 2022, Номер 145(1), С. 41 - 46

Опубликована: Дек. 23, 2022

A synthetic method for the reductive transformation of nitroarenes into ortho-aminated and -annulated products is reported. The operates via exhaustive deoxygenation by an organophosphorus catalyst a mild terminal reductant to access aryl nitrenes, which after ring expansion, are trapped amine nucleophiles give dearomatized 2-amino-3H-azepines. Treatment these ring-expanded intermediates with acyl electrophiles triggers 6π electrocyclization extrude nitrogen atom restore aromaticity phenyl ring, delivers C–H functionalization 2-aminoanilide benzimidazole products.

Язык: Английский

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Bi-Catalyzed Trifluoromethylation of C(sp²)–H Bonds under Light

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(47), С. 25538 - 25544

Опубликована: Ноя. 14, 2023

We disclose a Bi-catalyzed C–H trifluoromethylation of (hetero)arenes using CF3SO2Cl under light irradiation. The catalytic method permits the direct functionalization various heterocycles bearing distinct functional groups. structural and computational studies suggest that process occurs through an open-shell redox manifold at bismuth, comprising three unusual elementary steps for main group element. cycle starts with rapid oxidative addition to low-valent Bi(I) catalyst, followed by light-induced homolysis Bi(III)–O bond generate trifluoromethyl radical upon extrusion SO2, is closed hydrogen-atom transfer Bi(II) intermediate.

Язык: Английский

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Metallomimetic Chemistry of a Cationic, Geometrically Constrained Phosphine in the Catalytic Hydrodefluorination and Amination of Ar–F Bonds

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(6), С. 3786 - 3794

Опубликована: Фев. 4, 2023

The synthesis, isolation, and reactivity of a cationic, geometrically constrained σ3-P compound in the hexaphenyl-carbodiphosphoranyl-based pincer-type ligand (1+) are reported. 1+ reacts with electron-poor fluoroarenes via an oxidative addition-type reaction C-F bond to PIII-center, yielding new fluorophosphorane-type species (PV). This was used catalytic hydrodefluorination Ar-F bonds PhSiH3, C-N bond-forming cross-coupling reactions between aminosilanes. Importantly, these closely mimics mode action transition metal-based catalysts.

Язык: Английский

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