64701-03-7Relevant articles and documents
Synthesis of (+)-Antroquinonol and Analogues by Using Enantioselective Michael Reactions of Benzoquinone Monoketals
Hsu, Che-Sheng,Fang, Jim-Min
, p. 3809 - 3816 (2016/08/16)
(+)-Antroquinonol is an anticancer agent that was first isolated from the rare mushroom Antrodia cinnamomea, which is indigenous to Taiwan. In this study, (+)-antroquinonol is synthesized from benzoquinone monoketals by using an enantioselective Michael r
Efficient Coupling Reaction of Quinone Monoacetal with Phenols Leading to Phenol Biaryls
Kamitanaka, Tohru,Morimoto, Koji,Tsuboshima, Kohei,Koseki, Daichi,Takamuro, Hitoho,Dohi, Toshifumi,Kita, Yasuyuki
supporting information, p. 15535 - 15538 (2016/12/09)
A simple and efficient synthesis of phenol biaryls by the cross-couplings of quinone monoacetals (QMAs) and phenols is reported. The Br?nsted acid catalytic system in 1,1,1,3,3,3-hexafluoro-2-propanol was found to be particularly efficient for this transformation. This reaction can be extended to the synthesis of various phenol biaryls, including sterically hindered biaryls, with yields ranging from 58 to 90 % under mild reaction conditions and in a highly regiospecific manner.
Br?nsted acid-controlled [3 + 2] coupling reaction of quinone monoacetals with alkene nucleophiles: A catalytic system of perfluorinated acids and hydrogen bond donor for the construction of benzofurans
Hu, Yinjun,Kamitanaka, Tohru,Mishima, Yusuke,Dohi, Toshifumi,Kita, Yasuyuki
, p. 5530 - 5543 (2013/07/26)
We have developed an efficient Br?nsted acid-controlled strategy for the [3 + 2] coupling reaction of quinone monoacetals (QMAs) with nucleophilic alkenes, which is triggered by the particular use of a specific acid promoter, perfluorinated acid, and a solvent, fluoroalcohol. This new coupling reaction smoothly proceeded with high regiospecificity in regard with QMAs for introducing π-nucleophiles to only the carbon α to the carbonyl group, thereby providing diverse dihydrobenzofurans and derivatives with high yields, up to quantitative, under mild conditions in short reaction times. The choice of Br?nsted acid enabled us to avoid hydrolysis of the QMAs, which gives quinones, and the formation of discrete cationic species from the QMAs. Notably, further investigations in this study with regard to the acid have led to the findings that the originally stoichiometrically used acid could be reduced to a catalytic amount of 5 mol % loading or less and that the stoichiometry of the alkenes could be significantly improved down to only 1.2 equiv. The facts that only a minimal loading (5 mol %) of perfluoroterephthalic acid is required, readily available substrates can be used, and the regioselectivity can be controlled by the acid used make this coupling reaction very fascinating from a practical viewpoint.
