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

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(19), P. 8870 - 8882

Published: May 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.

Language: Английский

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Cobalt(III)-catalyzed asymmetric ring-opening of 7-oxabenzonorbornadienes via indole C–H functionalization

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Feb. 25, 2023

Abstract Asymmetric ring-opening of 7-oxabenzonorbornadienes is achieved via Co-catalyzed indole C–H functionalization. The utilization chiral Co-catalyst consisting a binaphthyl-derived trisubstituted cyclopentadienyl ligand resulted in high yields (up to 99%) and excellent enantioselectivity (>99% ee) for the target products with tolerance diverse functional groups. Opposite diastereoselectivities are obtained or Cp*CoI 2 CO. Combined experimental computational studies suggest β -oxygen elimination being selectivity-determining step reaction. Meanwhile, reactions 7-azabenzonorbornadiene could also be executed diastereodivergent manner.

Language: Английский

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A novel shear-stiffening supramolecular material derived from diboron structure

Science China Materials, Journal Year: 2023, Volume and Issue: 66(11), P. 4489 - 4498

Published: Oct. 8, 2023

Language: Английский

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Synthesis of naphthalene derivatives via nitrogen-to-carbon transmutation of isoquinolines

Science Advances, Journal Year: 2025, Volume and Issue: 11(5)

Published: Jan. 29, 2025

Heteroarene skeletal editing is gaining popularity in synthetic chemistry. Transmuting single atoms generates molecules that have distinctly varied properties, thereby fostering potent molecular exchanges can be extensively used to synthesize functional molecules. Herein, we present a convenient protocol for nitrogen-carbon single-atom transmutations isoquinolines, which inspired by the Wittig reaction and enables easy access substituted naphthalene derivatives. The uses an inexpensive commercially available phosphonium ylide as carbon source furnish wide range of naphthalenes. key success this transformation formation triene intermediate through ring opening, undergoes 6π-electrocyclization elimination processes afford product. Furthermore, strategy facile synthesis 13 C-labeled naphthalenes using CH 3 PPh I commercial C facilitates modifying directing group C─H functionalization.

Language: Английский

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Ir-Catalyzed Ligand-Free Directed C–H Borylation of Arenes and Pharmaceuticals: Detailed Mechanistic Understanding

The Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 87(6), P. 4360 - 4375

Published: March 7, 2022

An efficient method for Ir-catalyzed ligand free ortho borylation of arenes (such as, 2-phenoxypyridines, 2-anilinopyridines, benzylamines, benzylpiperazines, benzylmorpholines, benzylpyrrolidine, benzylpiperidines, benzylazepanes, α-amino acid derivatives, aminophenylethane and other important scaffolds) pharmaceuticals has been developed. The reaction underwent via an interesting mechanistic pathway, as revealed by the detailed investigations using kinetic isotope studies DFT calculations. catalytic cycle is found to involve intermediacy Ir-boryl complex where substrate C–H activation turnover determining step, intriguingly without any appreciable primary KIE. displays a broad range scope functional group tolerance. Numerous late-stage various molecules drugs were achieved this developed strategy. borylated compounds further converted into more valuable functionalities. Moreover, utilizing benefit B–N intramolecular interaction mono compounds, operationally simple selective diborylation 2-phenoxypyridines numerous functionalized arenes. Furthermore, synthetic utility showcased with removal pyridyl directing from product achieve phenol along ipso-borylation preparation 1,2-diborylated benzene.

Language: Английский

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Visible‐Light‐Induced, Single‐Metal‐Catalyzed, Directed C−H Functionalization: Metal‐Substrate‐Bound Complexes as Light‐Harvesting Agents

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(31)

Published: March 28, 2022

C-H functionalization represents one of the most rapidly advancing areas in organic synthesis and is regarded as key concepts to minimize ecological economic footprint synthesis. The ubiquity low reactivity bonds molecules, however, poses several challenges, often necessitates harsh reaction conditions achieve this goal, although it highly desirable reactions under mild conditions. Recently, reports uncovered a conceptually new approach towards functionalization, where single transition-metal complex can be used both photosensitizer catalyst promote bond absence an exogeneous photosensitizer. In Minireview, we will provide overview on recent achievements reactions, with emphasis photochemical modulation mechanism using such catalysts.

Language: Английский

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Ate complexes in organic synthesis: From ate reagents to ate catalysts

Green Synthesis and Catalysis, Journal Year: 2024, Volume and Issue: 5(3), P. 141 - 152

Published: May 8, 2024

The realm of application organometallic catalysis to organic synthesis has witnessed a transformative shift in recent years, owing much the evolution ate complexes from mere reagents versatile catalysts. Ate complexes, formed through coordination neutral Lewis acid with an anionic base, have emerged as pivotal intermediates that not only facilitate transformations but also serve efficient catalysts wide range chemical reactions. This review presents fascinating journey highlighting their development stoichiometric active Historically, were primarily regarded species essential for various metal-catalyzed transformations. However, constant research unveiled potential own right, reshaping landscape modern synthesis. In this minireview, we discuss role synthesis, early days reactive current stature catalytic pioneers offering glimpse into exciting future dynamic field.

Language: Английский

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Design, synthesis and visible-light-induced non-radical reactions of dual-functional Rh catalysts

Nature Synthesis, Journal Year: 2023, Volume and Issue: 2(6), P. 535 - 547

Published: March 30, 2023

Language: Английский

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Fast and Selective β-C–H Borylation of N-Heterocycles with a Supramolecular Iridium Catalyst: Circumventing Deactivation Pathways and Mechanistic Insights

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(12), P. 7715 - 7729

Published: May 24, 2023

Selective iridium-catalyzed C–H bond borylations of unbiased or directing-group-free substrates typically occur under long reaction times and mild temperatures in order to avoid unselective processes including catalyst deactivation. Herein, we describe a supramolecular approach that enables the borylation challenging pyiridines imidazoles very short (up 2 h) with negligible incubation period for activation. The is based on highly rigid zinc–porphyrin substrate-recognition site secondary coordination sphere triazolopyridine chelating fragment attached first at iridium. occurs from substrate located four chemical bonds apart molecular recognition selectivity being exclusively imposed by distance between active regardless nature N,N-chelating coordinating iridium as further supported density functional theory (DFT) calculations. Additional studies (control experiments, nuclear magnetic resonance, single-crystal X-ray diffraction) unraveled key deactivation pathways which up three different partners (water, methoxide ligands precursor, fragment) compete N-heterocycle binding catalyst. This fundamental understanding made possible identification featuring 4-methyl substitution pattern provides suitable balance steric electronic effects both primary spheres, thereby bypassing manifold pathways. DFT calculations indicated importance noncovalent interactions beyond stabilization intermediates transition sates.

Language: Английский

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Metal-Free Boron-Mediated ortho-C–H Hydroxylation of N-Benzyl-3,4,5-tribromopyrazoles

Organic Letters, Journal Year: 2022, Volume and Issue: 24(19), P. 3570 - 3575

Published: May 5, 2022

A novel route has been reported for C-H hydroxylation of benzyl compounds directed by a 3,4,5-tribromopyrazole auxiliary via boronation/oxidation using BBr3 and NaBO3·4H2O. The strategy exhibits outstanding site selectivity affords the corresponding phenols in moderate to excellent yields under metal-free conditions. Besides, this protocol can be achieved one pot, which is highly promising as practical method use multistep organic synthetic process.

Language: Английский

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