Applications of Halogen-Atom Transfer (XAT) for the Generation of Carbon Radicals in Synthetic Photochemistry and Photocatalysis DOI
Fabio Juliá, Timothée Constantin, Daniele Leonori

et al.

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 2292 - 2352

Published: Dec. 9, 2021

The halogen-atom transfer (XAT) is one of the most important and applied processes for generation carbon radicals in synthetic chemistry. In this review, we summarize highlight aspects associated with XAT impact it has had on photochemistry photocatalysis. organization material starts analysis mechanistic then follows a subdivision based nature reagents used halogen abstraction. This review aims to provide general overview fundamental concepts main agents involved objective offering tool understand facilitate development new radical strategies.

Language: Английский

3d Transition Metals for C–H Activation DOI
Parthasarathy Gandeepan, Thomas Müller, Daniel Zell

et al.

Chemical Reviews, Journal Year: 2018, Volume and Issue: 119(4), P. 2192 - 2452

Published: Nov. 27, 2018

C–H activation has surfaced as an increasingly powerful tool for molecular sciences, with notable applications to material crop protection, drug discovery, and pharmaceutical industries, among others. Despite major advances, the vast majority of these functionalizations required precious 4d or 5d transition metal catalysts. Given cost-effective sustainable nature earth-abundant first row metals, development less toxic, inexpensive 3d catalysts gained considerable recent momentum a significantly more environmentally-benign economically-attractive alternative. Herein, we provide comprehensive overview on until summer 2018.

Language: Английский

Citations

1980

Metallaphotoredox: The Merger of Photoredox and Transition Metal Catalysis DOI
Amy Chan, Ian B. Perry, Noah B. Bissonnette

et al.

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 1485 - 1542

Published: Nov. 18, 2021

The merger of photoredox catalysis with transition metal catalysis, termed metallaphotoredox has become a mainstay in synthetic methodology over the past decade. Metallaphotoredox combined unparalleled capacity for bond formation broad utility photoinduced electron- and energy-transfer processes. Photocatalytic substrate activation allowed engagement simple starting materials metal-mediated bond-forming Moreover, electron or energy transfer directly key organometallic intermediates provided novel modes entirely complementary to traditional catalytic platforms. This Review details contextualizes advancements molecule construction brought forth by metallaphotocatalysis.

Language: Английский

Citations

1174

Electrochemical strategies for C–H functionalization and C–N bond formation DOI Creative Commons
Markus D. Kärkäs

Chemical Society Reviews, Journal Year: 2018, Volume and Issue: 47(15), P. 5786 - 5865

Published: Jan. 1, 2018

This review provides an overview of the use electrochemistry as appealing platform for expediting carbon–hydrogen functionalization and carbon–nitrogen bond formation.

Language: Английский

Citations

880

Direct Photocatalyzed Hydrogen Atom Transfer (HAT) for Aliphatic C–H Bonds Elaboration DOI Creative Commons
Luca Capaldo, Davide Ravelli, Maurizio Fagnoni

et al.

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 1875 - 1924

Published: Aug. 6, 2021

Direct photocatalyzed hydrogen atom transfer (d-HAT) can be considered a method of choice for the elaboration aliphatic C–H bonds. In this manifold, photocatalyst (PCHAT) exploits energy photon to trigger homolytic cleavage such bonds in organic compounds. Selective bond may achieved by judicious abstractor (key parameters are electronic character and molecular structure), as well reaction additives. Different classes PCsHAT available, including aromatic ketones, xanthene dyes (Eosin Y), polyoxometalates, uranyl salts, metal-oxo porphyrin tris(amino)cyclopropenium radical dication. The processes (mainly C–C formation) most cases carried out under mild conditions with help visible light. aim review is offer comprehensive survey synthetic applications d-HAT.

Language: Английский

Citations

833

Mechanistic Studies in Photocatalysis DOI Open Access
Luca Buzzetti, Giacomo E. M. Crisenza, Paolo Melchiorre

et al.

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 58(12), P. 3730 - 3747

Published: Oct. 19, 2018

Abstract The fast‐moving fields of photoredox and photocatalysis have recently provided fresh opportunities to expand the potential synthetic organic chemistry. Advances in light‐mediated processes mainly been guided so far by empirical findings quest for reaction invention. general perception, however, is that entering a more mature phase where combination experimental mechanistic studies will play dominant role sustaining further innovation. This Review outlines key consider when developing photochemical process, best techniques available acquiring relevant information. discussion use selected case highlight how investigations can be instrumental guiding invention development synthetically useful photocatalytic transformations.

Language: Английский

Citations

767

Photocatalytic decarboxylative alkylations mediated by triphenylphosphine and sodium iodide DOI Open Access
Ming‐Chen Fu, Rui Shang, Bin Zhao

et al.

Science, Journal Year: 2019, Volume and Issue: 363(6434), P. 1429 - 1434

Published: March 28, 2019

Most photoredox catalysts in current use are precious metal complexes or synthetically elaborate organic dyes, the cost of which can impede their application for large-scale industrial processes. We found that a combination triphenylphosphine and sodium iodide under 456-nanometer irradiation by blue light-emitting diodes catalyze alkylation silyl enol ethers decarboxylative coupling with redox-active esters absence transition metals. Deaminative using Katritzky's N-alkylpyridinium salts trifluoromethylation Togni's reagent also demonstrated. Moreover, phosphine/iodide-based system catalyzes Minisci-type N-heterocycles operate tandem chiral phosphoric acids to achieve high enantioselectivity this reaction.

Language: Английский

Citations

669

Photoredox-Catalyzed C–H Functionalization Reactions DOI

Natalie Holmberg‐Douglas,

David A. Nicewicz

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 1925 - 2016

Published: Sept. 29, 2021

The fields of C–H functionalization and photoredox catalysis have garnered enormous interest utility in the past several decades. Many different scientific disciplines relied on strategies including natural product synthesis, drug discovery, radiolabeling, bioconjugation, materials, fine chemical synthesis. In this Review, we highlight use reactions. We separate review into inorganic/organometallic catalysts organic-based catalytic systems. Further subdivision by reaction class─either sp2 or sp3 functionalization─lends perspective tactical for these methods synthetic applications.

Language: Английский

Citations

651

A Toolbox Approach To Construct Broadly Applicable Metal-Free Catalysts for Photoredox Chemistry: Deliberate Tuning of Redox Potentials and Importance of Halogens in Donor–Acceptor Cyanoarenes DOI
Elisabeth Speckmeier, Tillmann G. Fischer, Kirsten Zeitler

et al.

Journal of the American Chemical Society, Journal Year: 2018, Volume and Issue: 140(45), P. 15353 - 15365

Published: Oct. 2, 2018

The targeted choice of specific photocatalysts has been shown to play a critical role for the successful realization challenging photoredox catalytic transformations. Herein, we demonstrate implementation rational design strategy series deliberate structural manipulations cyanoarene-based, purely organic donor-acceptor photocatalysts, using 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene (4CzIPN) as starting point. Systematic modifications both donor substituents well acceptors' molecular core allowed us identify strongly oxidizing reducing catalysts (e.g., an unprecedented detriflation unactivated naphthol triflate), which additionally offer remarkably balanced redox potentials with predictable trends. Especially halogen arene substitutions are instrumental our alterations catalysts' properties. Based on their preeminent electrochemical and photophysical characteristics, all novel, were evaluated in three challenging, mechanistically distinct classes benchmark reactions (either requiring balanced, highly or properties) enormous potential customizable that outperform complement prevailing typical best photocatalysts.

Language: Английский

Citations

618

Late-stage C–H functionalization offers new opportunities in drug discovery DOI
Lucas Guillemard, Nikolaos Kaplaneris, Lutz Ackermann

et al.

Nature Reviews Chemistry, Journal Year: 2021, Volume and Issue: 5(8), P. 522 - 545

Published: July 13, 2021

Language: Английский

Citations

596

Copper’s rapid ascent in visible-light photoredox catalysis DOI Open Access
Asik Hossain, Aditya Bhattacharyya, Oliver Reiser

et al.

Science, Journal Year: 2019, Volume and Issue: 364(6439)

Published: May 2, 2019

Visible-light photoredox catalysis offers a distinct activation mode complementary to thermal transition metal catalyzed reactions. The vast majority of processes capitalizes on precious ruthenium(II) or iridium(III) complexes that serve as single-electron reductants oxidants in their photoexcited states. As low-cost alternative, organic dyes are also frequently used but general suffer from lower photostability. Copper-based photocatalysts rapidly emerging, offering not only economic and ecological advantages otherwise inaccessible inner-sphere mechanisms, which have been successfully applied challenging transformations. Moreover, the combination conventional with copper(I) copper(II) salts has emerged an efficient dual catalytic system for cross-coupling

Language: Английский

Citations

574