Interfacial Synergy of Ni Single Atom/Clusters and MXene Enabling Semiconductor Quantum Dots Based Superior Photoredox Catalysis

ACS Catalysis, Journal Year: 2024, Volume and Issue: 15(1), P. 129 - 138

Published: Dec. 16, 2024

Semiconductor-based photocatalysis has evolved over the past decade into a prevalent approach for alcohol oxidation to afford corresponding carbonyl compounds or C–C/C–O coupled products. Nonetheless, photocatalytic oxidative lactonization of diols lactones still significantly lags behind, even though represent class ring moieties with excellent biological activities. In this work, we present high-performance visible-light-mediated and H2 Ti3C2Tx MXene-supported CdS quantum dots (QDs) Ni decoration (Ni/CdS/Ti3C2Tx). acts as two-dimensional platform immobilizing promote separation migration charge carriers, while concomitantly Cd2+ confinement effect retards hole-induced photocorrosion CdS. The unique modifications atomically dispersed species are either incorporated clusters in accelerate evolution, anchored single atom on efficient adsorption cyclization diols. optimized Ni/CdS/Ti3C2Tx exhibits remarkably enhanced activity lactone synthesis, which is 80.4 times higher than that blank CdS, along selectivity high durability. This work brings conceptual idea overcome well-known intrinsic drawback photoinduced decomposition semiconductor-based photocatalysts offers generic robust strategy utilizing cocatalyst active sites photoredox synthesis evolution.

Language: Английский

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The Carbene Chemistry of N-Sulfonyl Hydrazones: The Past, Present, and Future

Chemical Reviews, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 10, 2025

N-Sulfonyl hydrazones have been extensively used as operationally safe carbene precursors in modern organic synthesis due to their ready availability, facile functionalization, and environmental benignity. Over the past two decades, there has tremendous progress chemistry of N-sulfonyl presence transition metal catalysts, under metal-free conditions, or using photocatalysts photoirradiation conditions. Many transfer reactions are unique cannot be achieved by any alternative methods. The discovery novel development highly enantioselective new skeletal editing represent notable recent achievements hydrazones. This review describes overall made hydrazones, organized based on reaction types, spotlighting current state-of-the-art remaining challenges addressed future. Special emphasis is devoted identifying, describing, comparing scope limitations methodologies, key mechanistic scenarios, potential applications complex molecules.

Language: Английский

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Recent Advances in Theoretical Studies on Transition-Metal-Catalyzed Carbene Transformations

Accounts of Chemical Research, Journal Year: 2021, Volume and Issue: 54(14), P. 2905 - 2915

Published: July 7, 2021

ConspectusMetal carbene plays a vital role in modern organic synthesis. The neutral divalent carbon of metal renders it an active intermediate throughout range reactions. In experiments, diverse carbene-related transformation reactions have been established, including transition-metal-catalyzed cross-coupling using N-heterocyclic carbenes as ligands, insertion into σ bonds, cyclopropanations, ylide formation, and so forth. remarkable progress achieved synthetic chemistry, turn, has increased the demand for mechanistic studies chemistry. A thorough understanding reaction mechanisms can extend application scope compounds inspire rational design new reactions.Density functional theory (DFT) calculations performed our group to gain more insights This account focuses on computational with nucleophiles. generation or metal-ligated free subsequent pathways is discussed. According nucleophiles, three generalized models are summarized, intramolecular migratory carbene, intermolecular nucleophilic addition toward outer-sphere carbene.In general, mechanism commonly proposed since electrophilic carbon. From point view, also widely used because bonds formally occurs through this mechanism. An that form complex instead carbene. contains naked not coordinated center. case, transition-metal catalyst only Lewis acid, directly at Our results suggested facile step ligation could stabilize transition state well generated intermediate. low energy barrier due lack entropy penalty. Carbene formation from precursors usually rate-determining step, except addition, reactivity nucleophiles significant influence overall rate. We envision weak nucleophilicity would suppress addition. These showcase characteristics models, we hope will spur development

Language: Английский

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Remote sp² C–H Carboxylation via Catalytic 1,4-Ni Migration with CO₂

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(38), P. 16234 - 16239

Published: Sept. 10, 2020

A remote catalytic reductive sp2 C-H carboxylation of arenes with CO2 (1 bar) via 1,4-Ni migration is disclosed. This protocol constitutes the first reported to date, thus offering new vistas in Ni-catalyzed coupling arena while providing an unconventional platform for incorporating electrophilic sites at linkages.

Language: Английский

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Tandem Reactions involving 1,4‐Palladium Migrations

Chemistry - An Asian Journal, Journal Year: 2022, Volume and Issue: 17(15)

Published: June 6, 2022

Abstract Transition‐metal‐catalyzed tandem reactions have become a mainstay in organic chemistry owing to their high atom‐ and step‐economies. Metal‐migration‐based allow the engagement of simple starting materials for incorporating functional groups into certain positions constructing complex scaffolds, which provide novel means that are complementary traditional cross‐coupling or C−H activation processes. In light broad utility 1,4‐Pd migration reaction, this paper reviews its progress past two decades, summarizing process classifying it based on insertion, elimination, transmetalation, bond activation. Special emphasis is placed driving force Pd different mechanisms. Moreover, review also attempts summarize common strategies improving regio‐ site‐selectivities process.

Language: Английский

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Recent advances in transition metal migration involving reactions

Organic Chemistry Frontiers, Journal Year: 2020, Volume and Issue: 7(21), P. 3530 - 3556

Published: Jan. 1, 2020

In this review, various types of metal-migration involved methodologies, including palladium, rhodium, iron, cobalt, iridium, chromium, nickel, platinum, are summarized and demonstrated elaborately for giving a better access to field.

Language: Английский

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Modular Synthesis of Medium-Sized Fluorinated and Nonfluorinated Heterocyclic Lactones by Sequential CN-Bond-Cleaving Ring Expansion under Pd Catalysis

ACS Catalysis, Journal Year: 2020, Volume and Issue: 10(23), P. 14117 - 14126

Published: Nov. 18, 2020

Fluoro-functionalized heterocycles and medium-sized are both attractive skeletons in medicinal chemistry. However, the construction of fluoro-functionalized remains unexplored. Their synthesis represents a formidable challenge due to unfavorable entropic enthalpic factors that arise from rings unexpected properties induced by fluorinated groups. Here, we describe an efficient method for preparation highly functionalized gem-difluoromethylene N-heterocyclic lactones with 9- 11-membered sequential CN-bond-cleaving ring-expansion process using difluoro-oxindoles, various zwitterion precursors, Pd catalyst. This CN-cleaving expansion was extended synthesize nonfluorinated, α-keto-lactone moiety isatin derivatives. Additionally, monofluorinated nonfluorinated oxindoles were transformed into corresponding heterocyclic this protocol. The key transformation is cleavage unreactive amide CN bond, which smartly activated incorporation two neighboring electron-withdrawing groups assisted nucleophilic attack Pd-coordinated zwitterion. site-selective functionalization series products demonstrated show their synthetic utility. Mechanistic details cleavage/expansion proposed based on liquid chromatography–mass spectrometry (LC–MS) analyses.

Language: Английский

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Functionalization of Olefinic C−H Bonds by an Aryl‐to‐Vinyl 1,4‐Nickel Migration/Reductive Coupling Sequence

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(28)

Published: May 6, 2023

An attractive approach to selective functionalization of remote C-H bonds is a metal/hydride shift/cross-coupling reaction sequence. Complimentary the heavily exploited 1,2-nickel/hydride shift along an sp3 chain, chain-walking process, 1,4-nickel/hydride sp2 chain more complex. Here we report unprecedented aryl-to-vinyl reaction, in which migratory alkenylnickel species generated situ selectively trapped by one various coupling partners, such as isocyanates, alkyl bromides, aryl chlorides or alkynyl allowing regio- and stereoselective access trisubstituted alkenes. In contrast well-reported ipso-aryl reactions, this strategy provides alkenyl functionalized products with good yield excellent chemo-, E/Z-selectivity.

Language: Английский

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Alkyne Insertion Enabled Vinyl to Acyl 1,5‐Palladium Migration: Rapid Access to Substituted 5‐Membered‐Dihydrobenzofurans and Indolines

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(18)

Published: Feb. 21, 2023

"Through space" palladium/hydrogen shift is an efficient strategy to achieve selective functionalization of a specific remote C-H bond. Compared with relatively extensive exploited 1,4-palladium migration process, the relevant 1,5-Pd/H was far less investigated. We herein report novel pattern between vinyl and acyl group. Through pattern, rapid access 5-membered-dihydrobenzofuran indoline derivatives has been achieved. Further studies have unveiled unprecedented trifunctionalization (vinylation, alkynylation amination) phenyl ring through 1,5-palladium relayed decarbonylative Catellani type reaction. A series mechanistic investigations DFT calculations provided insights into reaction pathway. Notably, it that in our case prefers stepwise mechanism involving PdIV intermediate.

Language: Английский

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Palladium-catalyzed asymmetric carbene coupling en route to inherently chiral heptagon-containing polyarenes

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: April 18, 2024

Developing facile and direct synthesis routes for enantioselective construction of cyclic π-conjugated molecules is crucial. However, originate chirality from the distorted structure around heptagon-containing polyarenes largely overlooked, all-carbon remains a challenge. Herein, we present highly route fabricating all carbon via palladium-catalyzed carbene-based cross-coupling benzyl bromides N-arylsulfonylhydrazones. A wide range nonplanar, saddle-shaped tribenzocycloheptene derivatives are efficiently prepared in high yields with excellent enantioselectivities using this approach. In addition, stereochemical stability experiments show that these have inversion barriers.

Language: Английский

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