Unravelling the Effect of Water Addition in Consecutive Photocatalysis with Naphthalene Diimide

Caby, Sofia; Oliva, Laureano Marín; Bardagi, Javier Ivan

doi:10.1021/acs.joc.2c02172

Cited by 4 publications

(2 citation statements)

References 55 publications

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“…We were delighted to find that the yield of 2a increased significantly to 98% (Table , entry 6) when the reaction was carried out in the mixed solvent with the ratio of MeCN/H 2 O = 3:2 (v/v) by applying a 2.5 V constant potential for 2.5 h (4.55 F/mol). This striking improvement in output after water incorporation may be attributed to the fact that a specific amount of water promotes the desired aggregation of molecules for EDA complexation or stabilizes photoexcited radical anion species . Conducting the standard electrolysis in the dark provided only 23% of 2a (Table , entry 7), demonstrating the necessity of continuous light irradiation.…”

Section: Resultsmentioning

confidence: 99%

Investigating the Potency of a Phenalenyl-Based Photocatalyst under the Photoelectrochemical Condition for Intramolecular C–S Bond Formation

Sen,

Saha,

Raha Roy

2024

ACS Catal.

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Implementation of an organic molecular photocatalyst for photoelectrochemical (PEC) transformations has been a highly demanding aspect that has not yet been mapped out extensively. Herein, we have unveiled the efficacy of a phenalenyl-based organic photocatalyst toward photoelectrochemical intramolecular C−S bond construction reactions under mild conditions. This phenalenyl core, which contains a vacant NBMO, acts as an electron reservoir, thereby facilitating the formation of a contact ion pair with electron-rich organic systems through intramolecular electron transfer under photoexcitation and aiding in catalytic regeneration by anodic oxidation in a single pot. Detailed mechanistic investigation by using UV−visible spectral analysis, cyclic voltammetry experiments, and computational calculations revealed that the prior formation of an EDA complex between the phenalenyl-based photocatalyst and substrate triggers this PEC process. This unified strategy was successfully implemented in six different intramolecular C−S bond formation reactions to synthesize different heterocycles and make this protocol appealing for the synthesis of C−S bonds.

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Section: Resultsmentioning

confidence: 99%

Investigating the Potency of a Phenalenyl-Based Photocatalyst under the Photoelectrochemical Condition for Intramolecular C–S Bond Formation

Sen,

Saha,

Raha Roy

2024

ACS Catal.

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“…When applying the catalytic protocol to 2-allyloxy-1,3,5-tribromobenzene, the 5- exo - trig cyclized product 5a was obtained – albeit only in 28% yield – corroborating a radical mechanism. PDI catalysts have since found applications in other chemical transformations, their photophysical properties have been investigated further [ 40 ], and new variants [ 41 ] including heterogeneous versions have been introduced [ 42 – 44 ].…”

Section: Reviewmentioning

confidence: 99%

Photoredox catalysis harvesting multiple photon or electrochemical energies

Lepori,

Schmid,

Barham

2023

Beilstein J. Org. Chem.

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Photoredox catalysis (PRC) is a cutting-edge frontier for single electron-transfer (SET) reactions, enabling the generation of reactive intermediates for both oxidative and reductive processes via photon activation of a catalyst. Although this represents a significant step towards chemoselective and, more generally, sustainable chemistry, its efficacy is limited by the energy of visible light photons. Nowadays, excellent alternative conditions are available to overcome these limitations, harvesting two different but correlated concepts: the use of multi-photon processes such as consecutive photoinduced electron transfer (conPET) and the combination of photo- and electrochemistry in synthetic photoelectrochemistry (PEC). Herein, we review the most recent contributions to these fields in both oxidative and reductive activations of organic functional groups. New opportunities for organic chemists are captured, such as selective reactions employing super-oxidants and super-reductants to engage unactivated chemical feedstocks, and scalability up to gram scales in continuous flow. This review provides comparisons between the two techniques (multi-photon photoredox catalysis and PEC) to help the reader to fully understand their similarities, differences and potential applications and to therefore choose which method is the most appropriate for a given reaction, scale and purpose of a project.

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Shining Fresh Light on Complex Photoredox Mechanisms through Isolation of Intermediate Radical Anions

et al. 2023

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Photoredox catalysis (PRC) has gained enormous and wide-ranging interest in recent years but has also been subject to significant mechanistic uncertainty, even controversy. To provide a method by which the missing understanding can begin to be filled in, we demonstrate herein that it is possible to isolate as authentic materials the one-electron reduction products of representative PRC catalysts (PCs). Specifically, KC 8 reduction of both 9,10-dicyanoanthracene and a naphthalene monoamide derivative in the presence of a cryptand provides convenient access to the corresponding [K(crypt) + ][PC •− ] salts as clean materials that can be fully characterized by techniques including EPR and XRD. Because PC •− states are key intermediates in PRC reactions, such isolation allows for highly controlled study of these anions' specific reactivity and hence their mechanistic roles. As a demonstration of this principle, we show that these salts can be used to conveniently interrogate the mechanisms of recent, high-profile "conPET" and "e-PRC" reactions, which are currently the subject of both significant interest and acute controversy. Using very simple experiments, we are able to provide striking insights into these reactions' underlying mechanisms and to observe surprising levels of hidden complexity that would otherwise have been very challenging to identify and that emphasize the care and control that are needed when interrogating and interpreting PRC mechanisms. These studies provide a foundation for the study of a far broader range of questions around conPET, e-PRC, and other PRC reaction mechanisms in the future, using the same strategy of PC •− isolation.

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Unravelling the Effect of Water Addition in Consecutive Photocatalysis with Naphthalene Diimide

Cited by 4 publications

References 55 publications

Investigating the Potency of a Phenalenyl-Based Photocatalyst under the Photoelectrochemical Condition for Intramolecular C–S Bond Formation

Investigating the Potency of a Phenalenyl-Based Photocatalyst under the Photoelectrochemical Condition for Intramolecular C–S Bond Formation

Photoredox catalysis harvesting multiple photon or electrochemical energies

Shining Fresh Light on Complex Photoredox Mechanisms through Isolation of Intermediate Radical Anions

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