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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Advances in theE → ZIsomerization of Alkenes Using Small Molecule Photocatalysts

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 2650 - 2694

Published: Aug. 27, 2021

Geometrical E → Z alkene isomerization is intimately entwined in the historical fabric of organic photochemistry and enjoying a renaissance (Roth et al. Angew. Chem., Int. Ed. Engl. 1989 28, 1193–1207). This consequence fundamental stereochemical importance Z-alkenes, juxtaposed with frustrations thermal reactivity that are rooted microscopic reversibility. Accessing excited state paradigms allow this latter obstacle to be circumnavigated by exploiting subtle differences photophysical behavior substrate product chromophores: provides molecular basis for directionality. While direct irradiation operationally simple, photosensitization via selective energy transfer enables augmentation repertoire include substrates not directly photons. Through sustained innovation, an impressive portfolio tailored small molecule catalysts range triplet energies now widely available facilitate contra-thermodynamic thermo-neutral reactions generate Z-alkene fragments. review intended serve as practical guide covering geometric alkenes enabled catalysis from 2000 2020, logical sequel excellent treatment Dugave Demange (Chem. Rev. 2003 103, 2475–2532). The mechanistic foundations underpinning selectivity discussed together induction models rationales explain counterintuitive directionality these processes which very distinguish product. Implications subsequent stereospecific transformations, application total synthesis, regioselective polyene isomerization, spatiotemporal control pre-existing configuration broader sense discussed.

Language: Английский

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sp³ C–H Arylation and Alkylation Enabled by the Synergy of Triplet Excited Ketones and Nickel Catalysts

Journal of the American Chemical Society, Journal Year: 2018, Volume and Issue: 140(38), P. 12200 - 12209

Published: Sept. 5, 2018

Triplet ketone sensitizers are of central importance within the realm photochemical transformations. Although radical-type character triplet excited states diaryl ketones suggests viability for triggering hydrogen-atom transfer (HAT) and single-electron (SET) processes, among others, their use as multifaceted catalysts in C–C bond-formation via sp3 C–H functionalization alkane feedstocks still remains rather unexplored. Herein, we unlock a modular platform forging C(sp3)–C(sp2) C(sp3)–C(sp3) linkages from abundant bonds functional handles using synergy between nickel simple, cheap ketones. This method is distinguished by its wide scope that obtained starting precursors, thus complementing existing inner-sphere protocols or recent photoredox scenarios based on iridium polypyridyl complexes. Additionally, such provides new strategy streamlining synthesis complex molecules with high levels predictable site-selectivity preparative utility. Mechanistic experiments suggest abstraction occurs HAT state. We believe this study will contribute to more systematic utilization metallaphotoredox scenarios.

Language: Английский

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Photo-Biocatalysis: Biotransformations in the Presence of Light

ACS Catalysis, Journal Year: 2019, Volume and Issue: 9(5), P. 4115 - 4144

Published: April 9, 2019

Light has received increased attention for various chemical reactions but also in combination with biocatalytic reactions. Because currently only a few enzymatic are known, which per se require light, most transformations involving light and biocatalyst exploit either providing the cosubstrate or cofactor an appropriate redox state biotransformation. In selected cases, promiscuous activity of known enzymes presence could be induced. other approaches, light-induced have been combined step, were linear cascade. Finally, switchable moiety investigated to turn off/on tune actual reaction. This Review gives overview approaches using biocatalysis.

Language: Английский

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Visible‐Light‐Induced Homolysis of Earth‐Abundant Metal‐Substrate Complexes: A Complementary Activation Strategy in Photoredox Catalysis

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

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