Solvent-Free Pd-Catalyzed Heteroaryl–Aryl Coupling via C–H Bond Activation for the Synthesis of Extended Heteroaromatic Conjugated Molecules

Punzi, Angela; Capozzi, Maria Annunziata M.; Noja, Simone Di; Ragni, Roberta; Zappimbulso, Nicola; Farinola, Gianluca M.

doi:10.1021/acs.joc.8b01284

“…The terphenyl based diamine (HTP-BT-NH 2 ) annulated with electron-accepting BT unit was prepared according to the reported procedures. [36] The other two diamines (XTP-BT-NH 2 , X = F, Cl) were synthesized by a similar procedure while using 4,7…”

Section: Resultsmentioning

confidence: 99%

“…The terphenyl based diamine (HTP-BT-NH 2 ) annulated with electron-accepting BT unit was prepared according to the reported procedures. [36] The other two diamines (XTP-BT-NH 2 , X = F, Cl) were synthesized by a similar procedure while using 4,7 [1,2,5]thiadiazole as precursors (Supporting Information, Figures S1-S3 and Schemes S1-S3). The other building block of 4,4',4'',4'''-(pyrene-1,3,6,8-tetrayl)tetrabenzaldehyde (Py-CHO) was selected as the central docking site because it can easily create highly crystalline frameworks with excellent photoelectric performances.…”

Section: Resultsmentioning

confidence: 99%

Modulating Benzothiadiazole‐Based Covalent Organic Frameworks via Halogenation for Enhanced Photocatalytic Water Splitting

Chen

¹

,

Wang

²

,

Mo

³

et al. 2020

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Two‐dimensional covalent organic frameworks (2D COFs), an emerging class of crystalline porous polymers, have been recognized as a new platform for efficient solar‐to‐hydrogen energy conversion owing to their pre‐designable structures and tailor‐made functions. Herein, we demonstrate that slight modulation of the chemical structure of a typical photoactive 2D COF (Py‐HTP‐BT‐COF) via chlorination (Py‐ClTP‐BT‐COF) and fluorination (Py‐FTP‐BT‐COF) can lead to dramatically enhanced photocatalytic H2 evolution rates (HER=177.50 μmol h−1 with a high apparent quantum efficiency (AQE) of 8.45 % for Py‐ClTP‐BT‐COF). Halogen modulation at the photoactive benzothiadiazole moiety can efficiently suppress charge recombination and significantly reduce the energy barrier associated with the formation of H intermediate species (H*) on polymer surface. Our findings provide new prospects toward design and synthesis of highly active organic photocatalysts toward solar‐to‐chemical energy conversion.

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“…Py‐ X TP‐BT‐COFs ( X =H, F, Cl) were designed based on a well‐established D‐A built‐in strategy to enhance the charge separation efficiency and facilitate the light absorption. The terphenyl based diamine (HTP‐BT‐NH 2 ) annulated with electron‐accepting BT unit was prepared according to the reported procedures . The other two diamines ( X TP‐BT‐NH 2 , X =F, Cl) were synthesized by a similar procedure while using 4,7‐dibromo‐5,6‐difluorobenzo[ c ][1,2,5]thiadiazole or 4,7‐dibromo‐5,6‐dichlorobenzo[ c ][1,2,5]thiadiazole as precursors (Supporting Information, Figures S1–S3 and Schemes S1–S3).…”

Section: Resultsmentioning

confidence: 99%

Modulating Benzothiadiazole‐Based Covalent Organic Frameworks via Halogenation for Enhanced Photocatalytic Water Splitting

Chen

¹

,

Wang

²

,

Mo

³

et al. 2020

View full text Add to dashboard Cite

Two‐dimensional covalent organic frameworks (2D COFs), an emerging class of crystalline porous polymers, have been recognized as a new platform for efficient solar‐to‐hydrogen energy conversion owing to their pre‐designable structures and tailor‐made functions. Herein, we demonstrate that slight modulation of the chemical structure of a typical photoactive 2D COF (Py‐HTP‐BT‐COF) via chlorination (Py‐ClTP‐BT‐COF) and fluorination (Py‐FTP‐BT‐COF) can lead to dramatically enhanced photocatalytic H2 evolution rates (HER=177.50 μmol h−1 with a high apparent quantum efficiency (AQE) of 8.45 % for Py‐ClTP‐BT‐COF). Halogen modulation at the photoactive benzothiadiazole moiety can efficiently suppress charge recombination and significantly reduce the energy barrier associated with the formation of H intermediate species (H*) on polymer surface. Our findings provide new prospects toward design and synthesis of highly active organic photocatalysts toward solar‐to‐chemical energy conversion.

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“…In 2018, Farinola et al. extended the scope of the solvent‐free direct arylation to thienopyrrolodione, diketopyrrolopyrroles, benzodithiophene derivatives, and to fluorinated heteroarenes . The reactions were performed with aryl iodides and tolerated several functional groups on both the coupling partners (Scheme , b).…”

Section: Reactions In Green Solventsmentioning

confidence: 99%

Environmentally Benign Arylations of 5‐Membered Ring Heteroarenes by Pd‐Catalyzed C−H Bonds Activations

Mao

¹

,

Li

²

,

Shi

³

et al. 2018

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The palladium‐catalyzed functionalization of 5‐membered ring heteroaromatics, through a C−H bonds activation, for access to arylated heteroaromatics represent a very attractive alternative to more classical cross‐coupling reactions, as it saves steps and reduces the amount of wastes. Despite these advantages, these transformations initially suffered from major limitations in terms of sustainable chemistry concerning the reaction media, the nature of the catalyst, the catalyst loading, the aryl source or the regioselectivity control. Tremendous improvements allowing more sustainable reaction conditions using greener solvents, new aryl sources or employing easily removable catalysts and lower catalyst loadings have been described during the last decades. This review summarizes some of the most important contributions made in these directions.

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Solvent-Free Pd-Catalyzed Heteroaryl–Aryl Coupling via C–H Bond Activation for the Synthesis of Extended Heteroaromatic Conjugated Molecules

Cited by 28 publications

References 58 publications

Modulating Benzothiadiazole‐Based Covalent Organic Frameworks via Halogenation for Enhanced Photocatalytic Water Splitting

Modulating Benzothiadiazole‐Based Covalent Organic Frameworks via Halogenation for Enhanced Photocatalytic Water Splitting

Modulating Benzothiadiazole‐Based Covalent Organic Frameworks via Halogenation for Enhanced Photocatalytic Water Splitting

Environmentally Benign Arylations of 5‐Membered Ring Heteroarenes by Pd‐Catalyzed C−H Bonds Activations

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