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Efficient Synthesis of Anthraquinones from Diaryl Carboxylic Acids via Palladium(II)‐Catalyzed and Visible Light‐Mediated Transformations
Author(s) -
Kim Kiho,
Min Minsik,
Hong Sungwoo
Publication year - 2017
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.201601057
Subject(s) - chemistry , palladium , anthraquinones , photochemistry , potassium carbonate , visible spectrum , anthracene , benzoquinone , catalysis , cycloaddition , medicinal chemistry , organic chemistry , botany , physics , optoelectronics , biology
Irradiation of 9‐ester‐substituted anthracenes with visible light results in the formation of endoperoxides in the absence of a photocatalyst, which further undergo base‐assisted fragmentation to afford anthraquinones. The excited state species of anthracene generated by energy transfer, interacts with 3 O 2 to afford 1 O 2 by energy transfer and undergoes cycloaddition with 1 O 2 . By employing palladium(II)‐catalyzed and visible light‐mediated transformations, we have developed an efficient synthetic protocol for accessing diverse anthraquinones from readily available diaryl carboxylic acids. The optimal result was obtained with palladium(II) acetate, Ac‐Ile‐OH, benzoquinone and potassium carbonate in tert‐amyl alcohol under O 2 at 90 °C with irradiation from a 30 W fluorescent light bulb.