Synthesis and NMR-Investigation of Annelated Pyrrole Derivatives
摘要:
The synthesis of annelated pyrrole, namely isoindole derivatives by reaction of alpha,beta-unsaturated ketones, benzo- and naphthoquinone monoketals with tosylmethyl isocyanide is described. Moreover, detailed NMR spectroscopic studies (H-1, C-13) with the title compounds are presented.
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.
Development of a Cross‐Conjugated Vinylogous [4+2] Anionic Annulation and Application to the Total Synthesis of Natural Antibiotic (±)‐ABX
作者:Jing‐Kai Huang、Kak‐Shan Shia
DOI:10.1002/anie.201914657
日期:2020.4.16
vinylogous [4+2] anionic annulation has been newly developed, the cascade process of which has a high preference for regiochemical control and chemoselectivity, giving rise to exclusively Michael-type adducts in moderate to high yields (up to 94 %, 35 examples). By making use of this approach as a key operation, the first total synthesis of natural antibiotic ABX, in racemic form, has been successfully
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
Mixed Quinone Monoketals via Iodobenzene Diacetate Oxidation
作者:Amy E. Fleck、Julie A. Hobart、Gary W. Morrow
DOI:10.1080/00397919208021090
日期:1992.1
Abstract Oxidation of p-methoxyphenol, 4-methoxynaphthol and 4-acetamidophenol with iodobenzenediacetate in various alcohols as solvent afforded the corresponding mixed quinone or naphthoquinone monoketals in good yield. Oxidation of p-methoxyphenol in the presence of sorbyl alcohol led to in situ intramolecular Diels-Alder reactions proceeding by way of the corresponding mixed quinone monoketal.
Anionic [4+2] cycloaddition of furoindolones (e.g., 7 and 10) has been developed as an effective means to the synthesis of carbazoles. This reaction has been shown to be feasible with a wide variety of Michael acceptors to give carbazoles and fused carbazoles in good yields. The scope and limitations of the reaction have been briefly studied. The nature of N-protection of the furoindolones (cf. 7)