Metallaphotoredox: The Merger of Photoredox and Transition Metal Catalysis

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

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The Persistent Radical Effect in Organic Synthesis

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 59(1), P. 74 - 108

Published: May 22, 2019

Abstract Radical–radical couplings are mostly nearly diffusion‐controlled processes. Therefore, the selective cross‐coupling of two different radicals is challenging and not a synthetically valuable transformation. However, if have lifetimes they generated at equal rates, will become dominant process. This high cross‐selectivity based on kinetic phenomenon called persistent radical effect (PRE). In this Review, an explanation PRE supported by simulations simple model systems provided. Radical stabilities discussed within context their lifetimes, various examples PRE‐mediated radical–radical in synthesis summarized. It shown that restricted to coupling with transient radical. If one partner longer‐lived than other radical, operates achieved. important point expands scope chemistry. The Review divided into parts, namely 1) or organic 2) “radical–metal crossover reactions”; here, metal‐centered species more generally transition‐metal complexes able react discussed—a field has flourished recently.

Language: Английский

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Photoredox-Catalyzed C–H Functionalization Reactions

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

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Photochemical and Electrochemical Applications of Proton-Coupled Electron Transfer in Organic Synthesis

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 2017 - 2291

Published: Nov. 23, 2021

We present here a review of the photochemical and electrochemical applications multi-site proton-coupled electron transfer (MS-PCET) in organic synthesis. MS-PCETs are redox mechanisms which both an proton exchanged together, often concerted elementary step. As such, MS-PCET can function as non-classical mechanism for homolytic bond activation, providing opportunities to generate synthetically useful free radical intermediates directly from wide variety common functional groups. introduction practitioner’s guide reaction design, with emphasis on unique energetic selectivity features that characteristic this class. then chapters oxidative N–H, O–H, S–H, C–H homolysis methods, generation corresponding neutral species. Then, reductive PCET activations involving carbonyl, imine, other X═Y π-systems, heteroarenes, where ketyl, α-amino, heteroarene-derived radicals be generated. Finally, we asymmetric catalysis materials device applications. Within each chapter, subdivide by group undergoing homolysis, thereafter type transformation being promoted. Methods published prior end December 2020 presented.

Language: Английский

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Enantioselective Radical Reactions Using Chiral Catalysts

Chemical Reviews, Journal Year: 2022, Volume and Issue: 122(6), P. 5842 - 5976

Published: Jan. 24, 2022

Benefiting from the impressive increase in fundamental knowledge, last 20 years have shown a continuous burst of new ideas and consequently plethora catalytic methods for enantioselective radical reactions. This review aims to provide complete survey progress achieved over this latter period. The first part focuses on use chiral organocatalysts, these include catalysts covalently linked substrate those that interact with by weaker interactions like hydrogen bonds. second is devoted transition-metal redox catalysis which organized according increasing atomic number first-row transition metals (Ti, Cr, Fe, Mn, Co, Ni, Cu). Bioinspired manganese- iron-mediated hydroxylations oxidations are also discussed. A specific section dedicated reactivity Ru, Rh, Ir complexes as Lewis acids special focus at metal. Absorption photons result different events such energy transfer, single-electron hydrogen-atom transfer facilitating formation radicals. Organocatalysis has been successfully combined photocatalysts, opened pathways enlarging precursors available. merger photocatalysis organo- or metalla-photocatalysis brought novelty allowed discovery large original transformations. enzyme-catalyzed reactions involving intermediates largely benefit visible-light irradiation included review. provides comprehensive inventory goal detailing reaction mechanisms involved transformations any nonspecialist could find their own creativity invent yet unknown applications.

Language: Английский

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Reductive radical-polar crossover: traditional electrophiles in modern radical reactions

Chemical Science, Journal Year: 2019, Volume and Issue: 10(36), P. 8285 - 8291

Published: Jan. 1, 2019

The concept of reductive radical-polar crossover (RRPCO) reactions has recently emerged as a valuable and powerful tool to overcome limitations both radical traditional polar chemistry.

Language: Английский

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Stereoinduction in Metallaphotoredox Catalysis

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 60(4), P. 1714 - 1726

Published: July 17, 2020

Metallaphotoredox catalysis has evolved into an enabling platform to construct C(sp3 )-hybridized centers under remarkably mild reaction conditions. The cultivation of abundant radical precursor feedstocks significantly increased the scope transition-metal-catalyzed cross-couplings, especially with respect C(sp2 )-C(sp3 ) linkages. In recent years, considerable effort been devoted understanding origin stereoinduction in dual catalytic processes. this context, Ni- and Cu-catalyzed transformations have played a predominant role exploiting mode catalysis. Herein, we provide critical overview on progress enantioselective bond formations enabled by manifolds. Furthermore, selected stereochemical control elements within realm diastereoselective are discussed.

Language: Английский

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Nickel/Photo-Cocatalyzed Asymmetric Acyl-Carbamoylation of Alkenes

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(5), P. 2180 - 2186

Published: Jan. 23, 2020

An unprecedented asymmetric acyl-carbamoylation of pendant alkenes tethered on aryl carbamic chlorides with both aliphatic and aromatic aldehydes has been developed via the cooperative catalysis a chiral nickel-PHOX complex tetrabutylammonium decatungstate. This reaction represents first example merging hydrogen-atom-transfer photochemistry transition metal in difunctionalization alkenes. Using this protocol, variety oxindoles bearing challenging quaternary stereogenic center are furnished under mild conditions highly enantioselective manner.

Language: Английский

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Transition metal-catalysed allylic functionalization reactions involving radicals

Chemical Society Reviews, Journal Year: 2020, Volume and Issue: 49(17), P. 6186 - 6197

Published: Jan. 1, 2020

In this tutorial review, different types of transition metal-catalysed allylic functionalization reactions involving radicals are highlighted.

Language: Английский

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Dialkylation of 1,3-Dienes by Dual Photoredox and Chromium Catalysis

ACS Catalysis, Journal Year: 2019, Volume and Issue: 10(2), P. 1621 - 1627

Published: Dec. 18, 2019

The direct conversion of feedstock chemicals into value-added products is broad interest in chemical research. Herein, we present a regioselective and diastereoselective three-component dialkylation 1,3-dienes with Hantzsch esters aldehydes for the synthesis homoallylic alcohols. reaction enabled by dual photoredox chromium catalysis can also be performed enantioselectively employing chromium-bisoxazoline complexes.

Language: Английский

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