Energy transfer photocatalysis: exciting modes of reactivity

Chemical Society Reviews, Journal Year: 2024, Volume and Issue: 53(3), P. 1068 - 1089

Published: Jan. 1, 2024

Leveraging light energy to expose the ‘dark’ reactive states describes whole essence of triplet–triplet transfer. This offers an impressive opportunity conduct a multitude diverse reactions and access sought-after molecular motifs.

Language: Английский

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Accelerated photochemical reactions at oil-water interface exploiting melting point depression

Science, Journal Year: 2024, Volume and Issue: 383(6684), P. 750 - 756

Published: Feb. 15, 2024

Water can accelerate a variety of organic reactions far beyond the rates observed in classical solvents. However, using pure water as solvent introduces solubility constraints that have limited applicability efficient photochemistry particular. We report here formation aggregates between pairs arenes, heteroarenes, enamines, or esters with different electron affinities an aqueous medium, leading to oil-water phase boundary through substrate melting point depression. The active hydrogen atoms reactants engage bonds water, thereby accelerating photochemical reactions. This methodology realizes appealingly simple conditions for coupling complex solid molecules, including drug molecules are poorly soluble water.

Language: Английский

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Photocyclization by a triplet–triplet annihilation upconversion pair in water – avoiding UV-light and oxygen removal

Chemical Science, Journal Year: 2023, Volume and Issue: 14(40), P. 11040 - 11044

Published: Jan. 1, 2023

We present a formal [2 + 2]-cycloaddition of unsaturated ketones enabled by green-to-ultraviolet triplet-triplet annihilation upconversion (TTA-UC) pair, using commercially available Ru(bpy)32+ and pyrene as sensitizer annihilator, respectively. In the developed protocol, visible light irradiation at λmax = 520 nm allows for reaction to proceed without need UV-light aqueous medium eliminates oxygen removing protocols. Through this study, application readily pair is broadened include cyclization reactions. showcase utility system generating bicyclo[2.1.1]hexanes that are valuable bioisosteres ortho-substituted benzenes, promising motif pharmaceuticals.

Language: Английский

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A hydrazine-free photoredox catalytic synthesis of azines by reductive activation of readily available oxime esters

Green Chemistry, Journal Year: 2024, Volume and Issue: 26(11), P. 6446 - 6453

Published: Jan. 1, 2024

Herein, we present a novel, hydrazine-free photoredox catalyzed platform for azine synthesis using mild, simple reaction conditions.

Language: Английский

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Surfactant-Dependent Partitioning of Organics in Aqueous–Organic Reaction Systems

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(11), P. 8267 - 8271

Published: May 16, 2024

A fluorescence lifetime imaging microscopy (FLIM) technique characterizes surfactant-dependent partitioning of organics in a system that mimics Negishi-like cross-coupling reaction water, under synthetic concentrations, with emulsion droplets. Experimental data were not predictable from simple hydrophilic–lipophilic balances. The ionic surfactant cetrimonium chloride suppressed the reactivity metallic zinc surface, presumably through competitive binding and concurrent coating, finding may contribute to reduced performance surfactants bench-scale coupling reaction.

Language: Английский

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Solvent Dependency of Catalyst‐Substrate Aggregation Through π‐π Stacking in Photoredox Catalysis

ChemPhysChem, Journal Year: 2023, Volume and Issue: 24(20)

Published: July 21, 2023

Assemblies of photoredox catalysts and their target substrates prior to photoexcitation is a phenomenon naïvely overlooked by the majority synthetic chemists, but can have profound influences on reactivity selectivity in photocatalytic reactions. In this study, we determine aggregation states triarylamine radical cationic photocatalysts with various arene different solvents specifically parameterized polarizable molecular dynamics simulations. A π-stacking interaction previously implicated more expensive, less-representative quantum calculations confirmed. Critically, study presents new insights on: i) ability (MeCN vs DMF) make or break reaction promoting (MeCN) demoting (DMF) its catalyst-substrate assemblies, which determining factor for reactivity, ii) average "lifetimes" assemblies solution from dynamic simulation. We find that both ground state photoexcited state, remain intact periods often higher than 60 ps, rendering them ideally suitable undergo intra-assembly electron transfer reactions upon photoexcitation. Such aspects not addressed previous studies involving non-covalent assemblies.

Language: Английский

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Avoiding Oxygen Removal for Photochemical Reactions – towards Water as the Solvent

ChemPhotoChem, Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 23, 2024

Abstract Oxygen removing protocols have long been the standard approach to perform photoreactions. By encapsulating photosensitizers and reactants in tailored supramolecular assemblies, preservation of photoreactivity even presence molecular oxygen can be observed. Herein, we showcase some solutions that could render time‐consuming removal redundant photochemical synthesis. A focus has dedicated aqueous assemblies as potential reaction media. They present an attractive solution possibly useful not only for synthetic transformations, but also water purification, bio‐applications or biocatalysis. The included media are membranes, hydrogels, deep eutectic solvents peptide assemblies.

Language: Английский

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Oxygen tolerance in triplet-excited-state-based photocatalysis through compartmentalization

Chem Catalysis, Journal Year: 2023, Volume and Issue: 3(12), P. 100861 - 100861

Published: Dec. 1, 2023

Language: Английский

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