Visible‐Light‐Induced Organic Photochemical Reactions through Energy‐Transfer Pathways

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 58(6), P. 1586 - 1604

Published: May 18, 2018

Abstract Visible‐light photocatalysis is a rapidly developing and powerful strategy to initiate organic transformations, as it closely adheres the tenants of green sustainable chemistry. Generally, most visible‐light‐induced photochemical reactions occur through single‐electron transfer (SET) pathways. Recently, energy‐transfer (EnT) have received considerable attentions from synthetic community this provides distinct reaction pathway, remarkable achievements been made in field. In Review, we highlight recent advances EnT reactions.

Language: Английский

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Mechanistic Studies in Photocatalysis

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

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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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Visible‐Light‐Mediated Metal‐Free Difunctionalization of Alkenes with CO₂ and Silanes or C(sp³)−H Alkanes

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 57(52), P. 17220 - 17224

Published: Nov. 9, 2018

Catalytic alkene difunctionalization via Si-H and C-H activations represents an ideal atom- step-economic pathway for quick assembly of molecular complexity. We herein developed a visible-light-promoted metal-free alkenes using abundant CO2 readily available C(sp3 )-H bonds as feedstocks. Through the merger photoredox hydrogen-atom-transfer catalysis, variety value-added compounds, such β-silacarboxylic acids bearing γ-heteroatom (e.g., N, O, S) could be directly accessed from simple in redox-neutral fashion.

Language: Английский

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Positional and Geometrical Isomerisation of Alkenes: The Pinnacle of Atom Economy

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 58(39), P. 13654 - 13664

Published: June 25, 2019

Strategies to achieve spatiotemporal regulation of pre-existing alkenes via external stimuli are essential given the ubiquity feedstock olefins in chemistry and their downstream applications. Mirroring 1-0 switch that underpins mammalian vision through selective geometric isomerisation retinal, strategies manipulate 2D space by both positional chemical, thermal light-driven processes being intensively pursued. This minireview highlights current state art activating achieving directionality these fundamental chemical transformations.

Language: Английский

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Ligand‐to‐Metal Charge Transfer (LMCT) Photochemistry at 3d‐Metal Complexes: An Emerging Tool for Sustainable Organic Synthesis

ChemCatChem, Journal Year: 2022, Volume and Issue: 14(19)

Published: Aug. 11, 2022

Abstract Despite the rich photochemistry of 3d‐metal complexes, utilization excited‐state reactivity these compounds in organic synthesis has been historically overlooked. The advent photoredox catalysis changed perception synthetic chemists towards photochemistry, and nowadays potential photoinduced, outer‐sphere single‐electron transfer events is widely recognized. More recently, an emerging new mode photoactivation taken spotlight, based on inner‐sphere triggered by population ligand‐to‐metal charge‐transfer (LMCT) excited states. Contrarily to photoredox, LMCT‐activation does not rely matching redox potentials, offers unique profiles particularly well suited Earth‐abundant metal complexes. Those appealing features are propelling development methods using this blueprint generate highly reactive open‐shell species under mild conditions. aim contribution provide a didactical tool for comprehension concept facilitate methodologies achieve sustainable chemical transformations.

Language: Английский

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Nanoarchitectonics beyond Self‐Assembly: Challenges to Create Bio‐Like Hierarchic Organization

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 59(36), P. 15424 - 15446

Published: March 14, 2020

Abstract Incorporation of non‐equilibrium actions in the sequence self‐assembly processes would be an effective means to establish bio‐like high functionality hierarchical assemblies. As a novel methodology beyond self‐assembly, nanoarchitectonics, which has as its aim fabrication functional materials systems from nanoscopic units through methodological fusion nanotechnology with other scientific disciplines including organic synthesis, supramolecular chemistry, microfabrication, and bio‐process, been applied this strategy. The application factors conventional is discussed on basis examples directed assembly, Langmuir–Blodgett layer‐by‐layer assembly. In particular, structures using bio‐active components such proteins or by combination bio‐components two‐dimensional nanomaterials, are described. Methodologies described review article highlight possible approaches nanoarchitectonics concept for creation higher functionalities structural organization.

Language: Английский

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A Supported Bismuth Halide Perovskite Photocatalyst for Selective Aliphatic and Aromatic C–H Bond Activation

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 59(14), P. 5788 - 5796

Published: Dec. 18, 2019

Direct selective oxidation of hydrocarbons to oxygenates by O2 is challenging. Catalysts are limited the low activity and narrow application scope, main focus on active C-H bonds at benzylic positions. In this work, stable, lead-free, Cs3 Bi2 Br9 halide perovskites integrated within pore channels mesoporous SBA-15 silica demonstrate their photocatalytic potentials for bond activation. The composite photocatalysts can effectively oxidize (C5 C16 including aromatic aliphatic alkanes) with a conversion rate up 32900 μmol gcat-1 h-1 excellent selectivity (>99 %) towards aldehydes ketones under visible-light irradiation. Isotopic labeling, in situ spectroscopic studies, DFT calculations reveal that well-dispersed small perovskite nanoparticles (2-5 nm) possess enhanced electron-hole separation close contact facilitates C(sp3 )-H activation photoinduced charges.

Language: Английский

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Electrophotocatalytic Decarboxylative C−H Functionalization of Heteroarenes

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 59(26), P. 10626 - 10632

Published: March 30, 2020

Abstract Decarboxylative C−H functionalization reactions are highly attractive methods for forging carbon–carbon bonds considering their inherent step‐ and atom‐economical features the pervasiveness of carboxylic acids bonds. An ideal approach to achieve these dehydrogenative transformations is through hydrogen evolution without using any chemical oxidants. However, effective couplings by decarboxylative bond formation with proton reduction remain an unsolved challenge. Herein, we report electrophotocatalytic that merges organic electrochemistry photocatalysis efficient direct alkylation carbamoylation heteroaromatic compounds evolution. This method, which combines high efficiency selectivity in promoting decarboxylation superiority effecting reduction, enables coupling a wide range bases variety oxamic acids. Advantageously, this method scalable decagram amounts, applicable late‐stage drug molecules.

Language: Английский

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A Rational Approach to Organo‐Photocatalysis: Novel Designs and Structure‐Property Relationships

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 60(3), P. 1082 - 1097

Published: June 22, 2020

Organic photocatalysts are emerging as viable and more sustainable tools than metal complexes. Recently, the field of organo-photocatalysis has experienced an explosion in terms applications, redesign well-established systems, identification novel scaffolds. A rational approach to structural modification different is key accessing unprecedented reactivity, while improving their catalytic performances. We herein discuss concepts underpinning scaffold some most recently used analyze how specific changes alter physicochemical redox properties.

Language: Английский

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