Organocatalytic Asymmetric Formal [3+3] Cycloaddition Reactions of α,β-Unsaturated Aldehydes with Nazarov Reagents
作者:Ming-Kui Zhu、Qiang Wei、Liu-Zhu Gong
DOI:10.1002/adsc.200800174
日期:2008.6.9
An organocatalyticasymmetricformal [3+3] cycloaddition reaction of α,β-unsaturated aldehydes with Nazarov reagents promoted by prolinol derivatives afforded, after oxidation, 3,4-dihydropyranones in good yields with high enantioselectivities of up to 97% ee.
Geminal Diazides Derived from 1,3-Dicarbonyls: A Protocol for Synthesis
作者:Hellmuth Erhardt、Andreas P. Häring、Andreas Kotthaus、Markus Roggel、My Linh Tong、Phillip Biallas、Martin Jübermann、Fabian Mohr、Stefan F. Kirsch
DOI:10.1021/acs.joc.5b02328
日期:2015.12.18
Geminal diazides constitute a rare class of compounds where only a limited number of methods are available for their synthesis. We present the reaction of 1,3-dicarbonyl compounds (as exemplified by malonates, 3-oxoesters, and 1,3-diketones) with molecular iodine and sodium azide in aqueous DMSO providing a general access to geminal diazides. A broad range of geminal diazides with various structural
Primary−secondarydiaminecatalysts were used to catalyze the asymmetric Robinson annulation to synthesize multiply substituted fluorinated chiral cyclohexenones with two contiguous stereogenic centers, one of which is a fluorinated quaternary chiral center, with excellent enantioselectivities and diastereoselectivities in moderate to good yields.
Facile Synthesis of Polysubstituted Oxazoles via A Copper-Catalyzed Tandem Oxidative Cyclization
作者:Changfeng Wan、Jintang Zhang、Sujing Wang、Jinmin Fan、Zhiyong Wang
DOI:10.1021/ol100688c
日期:2010.5.21
A highly efficient synthesis of polysubstituted oxazoles was developed via a copper-catalyzed tandem oxidative cyclization. The desired products can be obtained from readily available starting materials under mild conditions. This is an attractive alternative method for the synthesis of oxazole derivatives.