Visible-Light-Promoted Palladium-Catalyzed C—H Amination for the Synthesis of Carbazolequinones

Han, Yang; Jiang, Weichao; Zhang, Jing; Peng, Jinsong; Chen, Chunxia

doi:10.6023/cjoc202104037

Cited by 2 publications

(2 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1 In particular, tetrahydrocarbazoles are embedded in many polycyclic ring systems. 2 For example, strychnine and brucine are found in the plant Strychnos nux-vomica , and feature multiple functional groups and complex stereochemical structures and have pharmacological actions at several neurotransmitter receptors (Fig. 1).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Assembly of tetracyclic tetrahydrocarbazoles via a visible-light promoted cascade process

Mei

Liu

et al. 2022

Org. Chem. Front.

View full text Add to dashboard Cite

show abstract

Section: Introductionmentioning

confidence: 99%

“…3,4 Due to the importance of tetrahydrocarbazole derivatives in organic synthesis and biological chemistry, the development of efficient methodologies for the assembly of these privileged molecular skeletons attracts great interest but remains a great challenge. 1,2,5…”

Section: Introductionmentioning

confidence: 99%

Assembly of tetracyclic tetrahydrocarbazoles via a visible-light promoted cascade process

Mei

Liu

et al. 2022

Org. Chem. Front.

View full text Add to dashboard Cite

show abstract

Selectively Aerobic Oxidation of Benzylic C—H Bonds Enabled by Dual Anthracene and Cerium Catalysis under Continuous-Flow Conditions^★

Yuanli,

Hui,

et al. 2023

Acta Chimica Sinica

View full text Add to dashboard Cite

The benzyl oxidation reaction serves as a crucial functional group transformation method in the field of organic synthesis. Regrettably, traditional benzyl oxidation reactions frequently necessitate harsh conditions, such as elevated temperatures and potent oxidizing agents. In contrast, this article showcases a highly selective catalytic benzylic oxidation executed within a continuous-flow microreactor. By harnessing the previously established cerium-alcohol complex's ligand to metal charge transfer (LMCT)-hydrogen atom transfer (HAT) activation mechanism and the anthracene-cerium synergistic catalytic system, a diverse array of aromatic ketones was synthesized from aryl alkanes with remarkable efficiency under ambient and aerobic conditions. The continuous-flow technology, endowed with unique advantages such as heightened illumination efficiency, superior gas-liquid mass transfer, repeatability, and scalability, has emerged as a powerful instrument for scaling-up photocatalytic reactions. In this process, under flow conditions, ethyl acetate solutions comprising Ce(NO3)3•6H2O, tetrabutylammonium bromide (TBABr), 9,10-dibromoanthracene (DBA), trichloroethanol (TCE), and ethylbenzene encountered and mixed with oxygen within the microreactor. Subsequently, a photocatalytic aerobic oxidation reaction occurred under visible light irradiation at room temperature, achieving complete conversion within a mere 5 min, and rapidly generated a series of aromatic ketones with good to excellent yields. Mechanistic studies indicated the paramount importance of the anthracene-derived catalyst DBA in achieving the heightened efficiency. Under visible light irradiation, the excited state DBA was initially oxidatively quenched with oxygen or peroxide species generated in the system, resulting in the formation of the DBA cationic free radical. Subsequently, the DBA cationic free radical underwent a single electron transfer (SET) process with the low-valent cerium (III) complex, consequently expediting the oxidative regeneration of the cerium (IV) catalyst and markedly boosting its catalytic efficacy. Eventually, this highly efficient catalytic system is characterized by its simplicity, mild reaction conditions, elevated selectivity, minimal waste production, and extensive applicability. Furthermore, it is effortlessly scalable and amenable to continuous production.

show abstract

Visible-Light-Promoted Palladium-Catalyzed C—H Amination for the Synthesis of Carbazolequinones

Cited by 2 publications

References 48 publications

Assembly of tetracyclic tetrahydrocarbazoles via a visible-light promoted cascade process

Assembly of tetracyclic tetrahydrocarbazoles via a visible-light promoted cascade process

Selectively Aerobic Oxidation of Benzylic C—H Bonds Enabled by Dual Anthracene and Cerium Catalysis under Continuous-Flow Conditions^★

Contact Info

Product

Resources

About

Visible-Light-Promoted Palladium-Catalyzed C—H Amination for the Synthesis of Carbazolequinones

Cited by 2 publications

References 48 publications

Assembly of tetracyclic tetrahydrocarbazoles via a visible-light promoted cascade process

Assembly of tetracyclic tetrahydrocarbazoles via a visible-light promoted cascade process

Selectively Aerobic Oxidation of Benzylic C—H Bonds Enabled by Dual Anthracene and Cerium Catalysis under Continuous-Flow Conditions★

Contact Info

Product

Resources

About

Selectively Aerobic Oxidation of Benzylic C—H Bonds Enabled by Dual Anthracene and Cerium Catalysis under Continuous-Flow Conditions^★