Visible Light-Induced Transition Metal Catalysis

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 1543 - 1625

Published: Oct. 8, 2021

In recent years, visible light-induced transition metal catalysis has emerged as a new paradigm in organic photocatalysis, which led to the discovery of unprecedented transformations well improvement known reactions. this subfield complex serves double duty by harvesting photon energy and then enabling bond forming/breaking events mostly via single catalytic cycle, thus contrasting established dual photocatalysis an exogenous photosensitizer is employed. addition, approach often synergistically combines catalyst–substrate interaction with photoinduced process, feature that uncommon conventional photoredox chemistry. This Review describes early development advances emerging field.

Language: Английский

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Remote C–H Functionalization via Selective Hydrogen Atom Transfer

Synthesis, Journal Year: 2018, Volume and Issue: 50(08), P. 1569 - 1586

Published: Feb. 12, 2018

The selective functionalization of remote C–H bonds via intramolecular hydrogen atom transfer (HAT) is transformative for organic synthesis. This radical-mediated strategy provides access to novel reactivity that complementary closed-shell pathways. As modern methods mild generation radicals are continually developed, inherent selectivity paradigms HAT mechanisms offer unparalleled opportunities developing new strategies functionalization. review outlines the history, recent advances, and mechanistic underpinnings as a guide addressing ongoing challenges in this arena. 1 Introduction 2 Nitrogen-Centered Radicals 2.1 sp3 N-Radical Initiation 2.2 sp2 3 Oxygen-Centered 3.1 Carbonyl Diradical 3.2 Alkoxy Radical 3.3 Non-alkoxy 4 Carbon-Centered 4.1 C-Radical 4.2 5 Conclusion

Language: Английский

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Toolbox for Distal C–H Bond Functionalizations in Organic Molecules

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(6), P. 5682 - 5841

Published: Oct. 18, 2021

Transition-metal-catalyzed C–H activation has developed a contemporary approach to the omnipresent area of retrosynthetic disconnection. Scientific researchers have been tempted take help this methodology plan their synthetic discourses. This paradigm shift helped in development industrial units as well, making synthesis natural products and pharmaceutical drugs step-economical. In vast zone bond activation, functionalization proximal bonds gained utmost popularity. Unlike bonds, distal is more strenuous requires distinctly specialized techniques. review, we compiled various methods adopted functionalize mechanistic insights within each these procedures, scope methodology. With give complete overview expeditious progress made field organic chemistry while also highlighting its pitfalls, thus leaving open for further modifications.

Language: Английский

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Transition Metal-Catalyzed Organic Reactions under Visible Light: Recent Developments and Future Perspectives

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

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Irradiation-Induced Heck Reaction of Unactivated Alkyl Halides at Room Temperature

Journal of the American Chemical Society, Journal Year: 2017, Volume and Issue: 139(50), P. 18307 - 18312

Published: Nov. 8, 2017

The palladium-catalyzed Mizoroki–Heck reaction is arguably one of the most significant carbon–carbon bond-construction reactions to be discovered in last 50 years, with a tremendous number applications production chemicals. This Nobel-Prize-winning transformation has yet overcome obstacle its general application range alkyl electrophiles, especially tertiary halides that possess eliminable β-hydrogen atoms. Whereas cross-coupling utilize ground-state reactivity palladium complexes under thermal conditions and generally apply single ligand system, we report Heck proceeds smoothly at room temperature variety tertiary, secondary, primary bromides upon irradiation blue light-emitting diodes presence dual phosphine system. We rationalize this unprecedented achieved by utilizing photoexcited-state complex enhance oxidative addition suppress undesired β-hydride elimination.

Language: Английский

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C–H functionalization reactions enabled by hydrogen atom transfer to carbon-centered radicals

Chemical Science, Journal Year: 2020, Volume and Issue: 11(48), P. 12974 - 12993

Published: Jan. 1, 2020

Intramolecular and intermolecular HAT to C-centered radicals enables selective C–H functionalization of organic molecules.

Language: Английский

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Catalysis with Palladium Complexes Photoexcited by Visible Light

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 58(34), P. 11586 - 11598

Published: Jan. 2, 2019

Abstract Palladium catalysis induced by visible light is an emerging field of catalysis. In contrast to classical reactions catalyzed Pd complexes in the ground state, which mostly proceed through two‐electron redox processes, mechanisms these new methods based on photoexcited usually operate transfer a single electron. Such processes lead putative hybrid Pd/radical species, exhibit both radical and Pd‐type reactivity. This Minireview highlights recent progress this rapidly growing area.

Language: Английский

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Visible‐Light‐Driven Palladium‐Catalyzed Radical Alkylation of C−H Bonds with Unactivated Alkyl Bromides

Angewandte Chemie International Edition, Journal Year: 2017, Volume and Issue: 56(49), P. 15683 - 15687

Published: Oct. 19, 2017

Abstract Reported herein is a novel visible‐light photoredox system with Pd(PPh 3 ) 4 as the sole catalyst for realization of first direct cross‐coupling C(sp )−H bonds in N‐aryl tetrahydroisoquinolines unactivated alkyl bromides. Moreover, intra‐ and intermolecular alkylations heteroarenes were also developed under mild reaction conditions. A variety tertiary, secondary, primary bromides undergo to generate )−C(sp 2 moderate excellent yields. These redox‐neutral reactions feature broad substrate scope (>60 examples), good functional‐group tolerance, facile generation quaternary centers. Mechanistic studies indicate that simple palladium complex acts photocatalyst radicals are involved process.

Language: Английский

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Visible Light-Induced Excited-State Transition-Metal Catalysis

Trends in Chemistry, Journal Year: 2019, Volume and Issue: 1(5), P. 510 - 523

Published: June 1, 2019

Language: Английский

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Three-Component, Interrupted Radical Heck/Allylic Substitution Cascade Involving Unactivated Alkyl Bromides

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(22), P. 10173 - 10183

Published: May 7, 2020

Developing efficient and selective strategies to approach complex architectures containing (multi)stereogenic centers has been a long-standing synthetic challenge in both academia industry. Catalytic cascade reactions represent powerful means of rapidly leveraging molecular complexity from simple feedstocks. Unfortunately, carrying out Heck-type involving unactivated (tertiary) alkyl halides remains an unmet owing unavoidable β-hydride elimination. Herein, we show that modular, practical, general palladium-catalyzed, radical three-component coupling can indeed overcome the aforementioned limitations through interrupted Heck/allylic substitution sequence mediated by visible light. Selective 1,4-difunctionalization 1,3-dienes, such as butadiene, achieved employing different commercially available nitrogen-, oxygen-, sulfur-, or carbon-based nucleophiles bromides (>130 examples, mostly >95:5 E/Z, >20:1 rr). Sequential C(sp3)–C(sp3) C–X (N, O, S) bonds have constructed efficiently with broad scope high functional group tolerance. The flexibility versatility strategy illustrated gram-scale reaction streamlined syntheses ether, sulfone, tertiary amine products, some which would be difficult access via currently established methods.

Language: Английский

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