Synthetic and Mechanistic Implications of Chlorine Photoelimination in Nickel/Photoredox C(sp3)–H Cross-Coupling DOI
Stavros K. Kariofillis, Abigail G. Doyle

Accounts of Chemical Research, Journal Year: 2021, Volume and Issue: 54(4), P. 988 - 1000

Published: Jan. 29, 2021

ConspectusIn recent years, the development of light-driven reactions has contributed numerous advances in synthetic organic chemistry. A particularly active research area combines photoredox catalysis with nickel to accomplish otherwise inaccessible cross-coupling reactions. In these reactions, catalyst absorbs light generate an electronically excited charge-transfer state that can engage electron or energy transfer a substrate and catalyst. Our group questioned whether photoinduced activation itself could also contribute new approaches cross-coupling. Over past 5 we have sought advance this hypothesis for suite mild site-selective C(sp3)–H chloride-containing coupling partners via photoelimination Ni–Cl bond.On basis report from Nocera laboratory, reasoned photolysis Ni(III) aryl chloride species, generated by single-electron oxidation typical Ni(II) intermediate cross-coupling, might allow catalytic generation chlorine atoms. Combining ability accept alkyl radicals, hypothesized photocatalytically atoms mediate hydrogen atom (HAT) bonds substrate-derived radical is captured Ni center was envisioned promote necessary reduction facilitate overall redox-neutral process. Overall, strategy would offer visible-light-driven mechanism formation enabled sequential capture two photons.As initial demonstration, developed Ni/photoredox-catalyzed α-oxy arylation cyclic acyclic ethers. This method extended formylation abundant complex chlorides through selective 2-functionalization 1,3-dioxolane. Seeking develop introduce carbon at all different states, explored trimethyl orthoformate, common laboratory solvent. We found orthoformate serves as source methyl methylation reaction β-scission tertiary upon chlorine-mediated HAT. Since capable abstracting unactivated bonds, our efforts been directed range feedstock chemicals, such alkanes toluenes, along late-stage intermediates, using chloroformates partners. platform enables access valuable transformations (hetero)aryl chlorides, which despite being most ubiquitous inexpensive halide partners, are rarely reactive Ni/photoredox catalysis.Little known about photophysics photochemistry organometallic complexes relevant conducted mechanistic investigations, including computational, spectroscopic, emission quenching, stoichiometric studies, These studies indicate operative described functionalization methods. More generally, illustrate catalysts cannot be ignored metallaphotoredox anticipate further understanding should design lead

Language: Английский

Transition Metal-Catalyzed Organic Reactions under Visible Light: Recent Developments and Future Perspectives DOI
Wan‐Min Cheng, Rui Shang

ACS Catalysis, Journal Year: 2020, Volume and Issue: 10(16), P. 9170 - 9196

Published: July 20, 2020

The development of transition metal (TM) catalysis for organic synthesis under visible light without recourse to typical photoredox catalysts has become a rapidly growing area research and been actively explored in the past several years. Distinct from extensively developed catalysis, which photocatalyst generally does not directly participate bond-forming process, photocatalyst/TM synergistic absorbs photon energy transfers TM catalyst through redox or transfer this Review focuses on summarizing recent developments photocatalytic reactions that use complexes both absorb catalytic bond formation involving covalently bonded intermediate. contents are categorized by used (Pd, Cu, Co, Ni, Mn, Au, Rh, Fe, Ru), with descending sequence according number examples reported each metal, provide an overview April 2020. Future perspectives personal opinions regarding expanding field also discussed.

Language: Английский

Citations

323
Strategic Use of Visible-Light Photoredox Catalysis in Natural Product Synthesis DOI
Spencer P. Pitre, Larry E. Overman

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 1717 - 1751

Published: July 7, 2021

Recent progress in the development of photocatalytic reactions promoted by visible light is leading to a renaissance use photochemistry construction structurally elaborate organic molecules. Because rich functionality found natural products, studies product total synthesis provide useful insights into functional group compatibility these new methods as well their impact on synthetic strategy. In this review, we examine syntheses published through end 2020 that employ visible-light photoredox catalytic step. To assist someone interested employing steps discussed, review organized largely nature bond formed

Language: Английский

Citations

323
Recent advances in photoredox and nickel dual-catalyzed cascade reactions: pushing the boundaries of complexity DOI Creative Commons
Chen Zhu, Huifeng Yue, Lingling Chu

et al.

Chemical Science, Journal Year: 2020, Volume and Issue: 11(16), P. 4051 - 4064

Published: Jan. 1, 2020

Cascade reactions that produce multiple chemical bonds in one synthetic operation are important the efficient construction of complex molecules.

Language: Английский

Citations

304
Photocatalysis in the Life Science Industry DOI
Lisa Candish,

Karl D. Collins,

Gemma C. Cook

et al.

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 2907 - 2980

Published: Sept. 24, 2021

In the pursuit of new pharmaceuticals and agrochemicals, chemists in life science industry require access to mild robust synthetic methodologies systematically modify chemical structures, explore novel space, enable efficient synthesis. this context, photocatalysis has emerged as a powerful technology for synthesis complex often highly functionalized molecules. This Review aims summarize published contributions field from industry, including research industrial-academic partnerships. An overview developed strategic applications synthesis, peptide functionalization, isotope labeling, both DNA-encoded traditional library is provided, along with summary state-of-the-art photoreactor effective upscaling photocatalytic reactions.

Language: Английский

Citations

292
Visible‐Light‐Induced Homolysis of Earth‐Abundant Metal‐Substrate Complexes: A Complementary Activation Strategy in Photoredox Catalysis DOI Creative Commons
Youssef Abderrazak, Aditya Bhattacharyya, Oliver Reiser

et al.

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(39), P. 21100 - 21115

Published: Feb. 18, 2021

Abstract The mainstream applications of visible‐light photoredox catalysis predominately involve outer‐sphere single‐electron transfer (SET) or energy (EnT) processes precious metal Ru II Ir III complexes organic dyes with low photostability. Earth‐abundant metal‐based M n L ‐type (M=metal, =polydentate ligands) are rapidly evolving as alternative photocatalysts they offer not only economic and ecological advantages but also access to the complementary inner‐sphere mechanistic modes, thereby transcending their inherent limitations ultrashort excited‐state lifetimes for use effective photocatalysts. generic process, termed visible‐light‐induced homolysis (VLIH), entails formation suitable light‐absorbing ligated metal–substrate (M ‐Z; Z=substrate) that can undergo homolytic cleavage generate n−1 Z . further transformations.

Language: Английский

Citations

291
Hantzsch esters: an emerging versatile class of reagents in photoredox catalyzed organic synthesis DOI

Peng‐Zi Wang,

Jia‐Rong Chen, Wen‐Jing Xiao

et al.

Organic & Biomolecular Chemistry, Journal Year: 2019, Volume and Issue: 17(29), P. 6936 - 6951

Published: Jan. 1, 2019

This minireview highlights the recent advances in chemistry of Hantzsch esters photoredox catalyzed organic synthesis, with particular emphasis placed on reaction mechanisms.

Language: Английский

Citations

290
Pyridinium Salts as Redox‐Active Functional Group Transfer Reagents DOI
Simon L. Rössler, Benson J. Jelier, Emmanuel Magnier

et al.

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 59(24), P. 9264 - 9280

Published: Oct. 10, 2019

Abstract In this Review, we highlight recent advances in the understanding and design of N‐functionalized pyridinium scaffolds as redox‐active, single‐electron, functional group transfer reagents. We provide a selection representative methods that demonstrate reactivity fundamental emerging field. The these reagents can be divided into two divergent pathways: homolytic fragmentation to liberate N‐bound substituent corresponding radical or an alternative heterolytic liberates N‐centered radical. A short description elementary steps involved induced by single‐electron is also critically discussed guide readers towards processes thought occur under conditions.

Language: Английский

Citations

255
Catalytic three-component dicarbofunctionalization reactions involving radical capture by nickel DOI
Shengqing Zhu, Xian Zhao, Huan Li

et al.

Chemical Society Reviews, Journal Year: 2021, Volume and Issue: 50(19), P. 10836 - 10856

Published: Jan. 1, 2021

The catalytic dicarbofunctionalization of unsaturated π bonds represents a powerful platform for the rapid construction complex motifs. Despite remarkable progress, novel and efficient methods achieving such transformations under milder conditions with chemo-, regio-, stereoselectivity still remain significant challenge; thus, their development is highly desirable. Recently, merging nickel catalysis radical chemistry offers new benign unprecedented reactivity selectivity. In this review, we summarize recent advances in area by underpinning domino involving capture to provide clear overview reaction designs mechanistic scenarios.

Language: Английский

Citations

240
Developments in Photoredox/Nickel Dual-Catalyzed 1,2-Difunctionalizations DOI Creative Commons
Shorouk O. Badir,

Gary A. Molander

Chem, Journal Year: 2020, Volume and Issue: 6(6), P. 1327 - 1339

Published: June 1, 2020

Language: Английский

Citations

234
3d-d Excited States of Ni(II) Complexes Relevant to Photoredox Catalysis: Spectroscopic Identification and Mechanistic Implications DOI
Stephen I. Ting, Sofia Garakyaraghi,

Chelsea M. Taliaferro

et al.

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(12), P. 5800 - 5810

Published: March 9, 2020

Synthetic organic chemistry has seen major advances due to the merger of nickel and photoredox catalysis. A growing number Ni-photoredox reactions are proposed involve generation excited species, sometimes even in absence a catalyst. To gain insights about these states, two our groups previously studied photophysics Ni(t-Bubpy)(o-Tol)Cl, which is representative intermediates many reactions. This complex was found have long-lived state (τ = 4 ns), computationally assigned as metal-to-ligand charge transfer (MLCT) with an energy 1.6 eV (38 kcal/mol). work evaluates computational assignment experimentally using series related complexes. Ultrafast UV-Vis mid-IR transient absorption data suggest that MLCT generated initially upon excitation but decays 3d-d rather than 3MLCT character. Dynamic cis,trans-isomerization square planar complexes observed dark 1H NMR techniques, supporting this tetrahedral accessible at ambient temperature. Through combination studies, determined lie ∼0.5 (12 kcal/mol) above ground state. Because features weak Ni-aryl bond, Ni(II) can undergo Ni homolysis generate aryl radicals Ni(I), both supported experimentally. Thus, photoinduced offers novel mechanism initiating catalysis by Ni(I).

Language: Английский

Citations

232