Li Yangyan, Su Xiao, Zhou Wei, Li Wenbo, Zhang Junliang
Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, 3663, N. Zhongshan Road, Shanghai, 200062 (P.R. China) http://faculty.ecnu.edu.cn/s/1811/main.jspy.
Chemistry. 2015 Mar 9;21(11):4224-8. doi: 10.1002/chem.201406475. Epub 2015 Jan 28.
Cyclobutenones have been explored as a new type of chiral 1,4-dipole four-carbon synthon, which readily undergoes organophosphine-mediated C-C bond cleavage and asymmetric intermolecular 1,4-dipolar spiroannulation with isatylidenemalononitrile in the presence of amino acid-derived chiral phosphine catalyst to furnish enantioenriched 3-spirocyclohexenone 2-oxindoles in good yield with up to 87% ee. To our knowledge, this is the first example of asymmetric transformation of cyclobutenones and the phosphine-catalyzed asymmetric 1,4-dipolar cycloaddition consisting of C-C bond activation is unprecedented.
环丁烯酮已被开发为一种新型手性1,4-偶极四碳合成子，在氨基酸衍生的手性膦催化剂存在下，它很容易发生有机膦介导的C-C键裂解以及与异亚吲哚基丙二腈的不对称分子间1,4-偶极螺环化反应，以良好的产率提供对映体富集的3-螺环己烯酮-2-氧化吲哚，对映体过量率高达87%。据我们所知，这是环丁烯酮不对称转化的首个例子，且由C-C键活化构成的膦催化不对称1,4-偶极环加成反应是前所未有的。
