Engineering Semiconductor Quantum Dots for Selectivity Switch on High-Performance Heterogeneous Coupling Photosynthesis

ACS Nano, Journal Year: 2022, Volume and Issue: 16(10), P. 17444 - 17453

Published: Sept. 28, 2022

Semiconductor-based photoredox catalysis brings an innovative strategy for sustainable organic transformation (e.g., C-C/C-X bond formation), via radical coupling under mild conditions. However, since semiconductors interact with photogenerated radicals unselectively, the precise control of selectivity such synthesis by steering conversion is extremely challenging. Here, judicious design a structurally well-defined and atomically dispersed cocatalyst over semiconductor quantum dots, we demonstrate switch on high-performance selective heterogeneous photosynthesis C-C or C-N along hydrogen production Ni-oxo cluster single Pd atom-decorated CdS dots crafted onto SiO2 support. Mechanistic studies unveil that Ph(•CH)NH2 PhCH2NH2•+ act as dominant intermediates divergent coupled vicinal diamines imines, respectively enabled clusters assisted radical-radical atom-assisted addition-elimination. This work overcomes pervasive difficulties regulation in semiconductor-based photochemical synthesis, highlighting vista utilizing cocatalysts active sites to maneuver unselective engineering toward photosynthesis.

Language: Английский

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Copper-Catalyzed Trifluoromethylation of Alkyl Bromides

Journal of the American Chemical Society, Journal Year: 2019, Volume and Issue: 141(17), P. 6853 - 6858

Published: April 15, 2019

Copper oxidative addition into organohalides is a challenging two-electron process. In contrast, formal of copper to Csp2 carbon–bromine bonds can be accomplished by employing latent silyl radicals under photoredox conditions. This novel paradigm for has now been applied Cu-catalyzed cross-coupling Csp3-bromides. Specifically, copper/photoredox dual catalytic system the coupling alkyl bromides with trifluoromethyl groups presented. operationally simple and robust protocol successfully converts variety alkyl, allyl, benzyl, heterobenzyl corresponding trifluoromethanes.

Language: Английский

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Nickel and Palladium Catalysis: Stronger Demand than Ever

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(2), P. 1180 - 1200

Published: Jan. 5, 2022

Key similarities and differences of Pd Ni in catalytic systems are discussed. Overall, catalyze a vast number similar C–C C–heteroatom bond-forming reactions. However, the smaller atomic radius lower electronegativity Ni, as well more negative redox potentials low-valent species, often provide higher reactivity oxidative addition or insertion reactions persistence alkyl-Ni intermediates against β-hydrogen elimination, thus enabling activation reluctant electrophiles, including alkyl electrophiles. Another key point relates to stability open-shell electronic configurations Ni(I) Ni(III) compared with Pd(I) Pd(III). Nickel very involve interconvertible Ni(n+) active species variable oxidation states (Ni(0), Ni(I), Ni(II), Ni(III)). In contrast, involving Pd(III) still relatively less developed may require facilitation by special ligands merging photo- electrocatalysis. high Pd(n+) ensure their facile reduction Pd(0) under assistance numerous reagents solvents, providing concentrations molecular Pd1(0) complexes that can reversibly aggregate into Pdn clusters nanoparticles form cocktail Pdn(0) various nuclearities (i.e., values "n"). Ni(0) strong reductants; they sensitive deactivation air other oxidizers and, consequence, operate at catalyst loadings than palladium same The ease robustness versatility for catalysis, whereas variety enables diverse uncommon reactivity, albeit requiring efforts stabilization nickel systems. As discussion, we note easily "cocktail particles" different but (Pd1, Pdn, NPs), behave species" is stable nuclearities. Undoubtedly, there stronger demand ever not only develop improved efficient catalysts also understand mechanisms

Language: Английский

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Activation of C–O and C–N Bonds Using Non-Precious-Metal Catalysis

ACS Catalysis, Journal Year: 2020, Volume and Issue: 10(20), P. 12109 - 12126

Published: Sept. 10, 2020

ADVERTISEMENT RETURN TO ISSUEPREVViewpointNEXTActivation of C–O and C–N Bonds Using Non-Precious-Metal CatalysisTimothy B. BoitTimothy BoitDepartment Chemistry Biochemistry, University California, Los Angeles, California 90095, United StatesMore by Timothy Boit, Ana S. BulgerAna BulgerDepartment Bulger, Jacob E. DanderJacob DanderDepartment Dander, Neil K. Garg*Neil GargDepartment States*E-mail: [email protected]More Garghttp://orcid.org/0000-0002-7793-2629Cite this: ACS Catal. 2020, 10, 20, 12109–12126Publication Date (Web):September 2020Publication History Received30 July 2020Published online10 September inissue 16 October 2020https://pubs.acs.org/doi/10.1021/acscatal.0c03334https://doi.org/10.1021/acscatal.0c03334article-commentaryACS PublicationsCopyright © 2020 American Chemical Society. This publication is available under these Terms Use. Request reuse permissions free to access through this site. Learn MoreArticle Views15643Altmetric-Citations116LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum full text article downloads since November 2008 (both PDF HTML) across all institutions individuals. These metrics regularly updated reflect usage leading up last few days.Citations number other articles citing article, calculated Crossref daily. Find more information about citation counts.The Altmetric Attention Score a quantitative measure attention that research has received online. Clicking on donut icon will load page at altmetric.com with additional details score social media presence for given article. how calculated. Share Add toView InAdd Full Text ReferenceAdd Description ExportRISCitationCitation abstractCitation referencesMore Options onFacebookTwitterWechatLinked InRedditEmail (3 MB) Get e-AlertscloseSUBJECTS:Alkyls,Amides,Coupling reactions,Cross coupling reaction,Organic compounds e-Alerts

Language: Английский

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Recent advances in molecular oxygen activation via photocatalysis and its application in oxidation reactions

Chemical Engineering Journal, Journal Year: 2021, Volume and Issue: 421, P. 129915 - 129915

Published: April 24, 2021

Language: Английский

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Efficient and Direct Functionalization of Allylic sp³ C−H Bonds with Concomitant CO₂ Reduction

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(41)

Published: Aug. 26, 2023

Solar-driven CO2 reduction integrated with C-C/C-X bond-forming organic synthesis represents a substantially untapped opportunity to simultaneously tackle carbon neutrality and create an atom-/redox-economical chemical synthesis. Herein, we demonstrate the first cooperative photoredox catalysis of efficient tunable syngas, paired direct alkylation/arylation unactivated allylic sp3 C-H bonds for accessing C-C products, over SiO2 -supported single Ni atoms-decorated CdS quantum dots (QDs). Our protocol not only bypasses additional oxidant/reductant pre-functionalization substrates, affording broad products moderate excellent yields, but also produces syngas CO/H2 ratios (1 : 2-5 1). Such win-win coupling highlights high atom-, step- redox-economy, good durability, illuminating tantalizing possibility renewable sunlight-driven feedstocks manufacturing industry.

Language: Английский

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Elucidating electron-transfer events in polypyridine nickel complexes for reductive coupling reactions

Nature Catalysis, Journal Year: 2023, Volume and Issue: 6(3), P. 244 - 253

Published: March 9, 2023

Language: Английский

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General room-temperature Suzuki–Miyaura polymerization for organic electronics

Nature Materials, Journal Year: 2024, Volume and Issue: 23(5), P. 695 - 702

Published: Jan. 29, 2024

Language: Английский

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Insights into Recent Nickel-Catalyzed Reductive and Redox C–C Coupling of Electrophiles, C(sp³)–H Bonds and Alkenes

Accounts of Chemical Research, Journal Year: 2024, Volume and Issue: 57(8), P. 1149 - 1162

Published: March 28, 2024

ConspectusTransition metal-catalyzed reductive cross-coupling of two carbon electrophiles, also known as cross-electrophile coupling (XEC), has transformed the landscape C–C chemistry. Nickel catalysts, in particular, have demonstrated exceptional performance facilitating XEC reactions, allowing for diverse elegant transformations by employing various electrophiles to forge bonds. Nevertheless, several crucial challenges remain be addressed. First, intrinsic chemoselectivity between structurally similar Ni-catalyzed C(sp3)–C(sp3) and C(sp2)–C(sp2) not been well understood; this necessitates an excess one partners achieve synthetically useful outcomes. Second, substitution economically environmentally benign nonmetal reductants Zn/Mn can help scale up reactions avoid trace metals pharmaceutical products, but research direction progressed slowly. Finally, it is highly warranted leverage mechanistic insights from develop innovative thermoredox protocols, specifically designed tackle associated with difficult substrates such C(sp3)–H bonds unactivated alkenes.In Account, we address aforementioned issues reviewing our recent work on C–X C–O strategy alkenes, use diboron esters coupling. We focus perspectives transformations, particularly how key C–NiIII–C intermediates are generated, order explain chemoselective regioselective results. The Account consists four sections. discuss Zn/Mn-mediated bond formations based selected alkyl/aryl, allyl/benzyl, other electrophiles. describe versatile C(sp3)–C(sp2) couplings, emphasis consideration construction Third, leveraging C(sp3)–O effective C(sp3)–C formation via situ halogenation alcohols preparation α-vinylated -arylated unusual amino esters. In final section, illustrate functionalization challenging aryl alkyl halides afford taking advantage compatibility Zn oxidant di-tert-butylperoxide (DTBP). Furthermore, a SiH/DTBP-mediated hydrodimerization terminal alkenes selectively head-to-head methyl branched This process, conducted presence or absence catalytic CuBr2, provides solution long-standing challenge: site-selective hydrocoupling produce

Language: Английский

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Engaging Radicals in Transition Metal-Catalyzed Cross-Coupling with Alkyl Electrophiles: Recent Advances

ACS Catalysis, Journal Year: 2017, Volume and Issue: 7(7), P. 4697 - 4706

Published: June 7, 2017

Transition metal-catalyzed cross-coupling reactions have created an epoch in modern synthetic organic chemistry, offering a variety of insights into retrosynthetic tactics for synthesizing targeted complex molecules medicine and materials-based applications. Despite numerous types combinations nucleophiles, electrophiles, transition metal catalysts available the reactions, construction covalent bonds that include sp3-hybridized carbon(s) remains challenge because inherent diverse reactivity alkyl species (i.e., halides metals) involved catalytic cycle. Methods leveraging radicals recently emerged, which will aid realization this goal. This perspective highlights discusses recent advances engage C(sp3)–N C(sp3)–Si bond formation with as well use carboxylic acid derivatives surrogates decarboxylative C(sp3)–C(sp2)/C(sp3)/B couplings.

Language: Английский

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