Amino Acid Derived Phosphine-Catalyzed Enantioselective 1,4-Dipolar Spiroannulation of Cyclobutenones and Isatylidenemalononitrile
作者:Yangyan Li、Xiao Su、Wei Zhou、Wenbo Li、Junliang Zhang
DOI:10.1002/chem.201406475
日期:2015.3.9
Cyclobutenones have been explored as a new type of chiral 1,4‐dipole four‐carbon synthon, which readily undergoes organophosphine‐mediated CC 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
Cyclobutenones已探索作为一种新型手性1,4-偶极四碳的合成子,哪个容易经历有机膦-体介导C C键的裂解和不对称分子间1,4-偶极spiroannulation与isatylidenemalononitrile中的氨基酸衍生的存在下手性膦催化剂可提供高收率的对映体富集的3-螺环己烯酮2-氧吲哚,ee最高可达87% 。据我们所知,这是环丁烯酮不对称转化的第一个例子,由膦键活化的磷化氢催化的不对称1,4-偶极环加成反应是前所未有的。