Coupling of Quinone Monoacetals Promoted by Sandwiched Brønsted Acids: Synthesis of Oxygenated Biaryls
作者:Toshifumi Dohi、Naohiko Washimi、Tohru Kamitanaka、Kei-ichiro Fukushima、Yasuyuki Kita
DOI:10.1002/anie.201101646
日期:2011.6.27
Unusual protons: Brønsted acids sandwiched between sheets of solid acids, such as montmorillonites, activated quinone monoacetals 1 to selectively react with aromatic nucleophiles 2 in an unprecedented substitution reaction. The syntheticutility of the strategy for obtaining highly oxygenated biaryls 3 is highlighted by the synthesis of gilvocarcin aglycones.
Brønsted 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
作者:Yinjun Hu、Tohru Kamitanaka、Yusuke Mishima、Toshifumi Dohi、Yasuyuki Kita
DOI:10.1021/jo400613z
日期:2013.6.7
We have developed an efficient Brønsted acid-controlled strategy for the [3 + 2] coupling reaction of quinonemonoacetals (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
Efficient Synthesis of Oxygenated Terphenyls and Other Oligomers: Sequential Arylation Reactions Through Phenol Oxidation-Rearomatization
作者:Toshifumi Dohi、Tohru Kamitanaka、Shohei Watanabe、Yinjun Hu、Naohiko Washimi、Yasuyuki Kita
DOI:10.1002/chem.201202086
日期:2012.10.22
One by one: Starting from simple phenols, a diverse series of oxygenatedterphenyl compounds can be prepared in a concise and practical manner using sequentialarylationreactions involving phenol oxidation/rearomatization and quinone monoacetal intermediates (see scheme). Many of the terphenyl products can be used for preparing well‐defined oligomers and, furthermore, contain valuable functional groups