Core Scaffold-Inspired Stereoselective Synthesis of Spiropyrazolones via an Organocatalytic Michael/Cyclization Sequence

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• 作者：Luping Liu ; Yuan Zhong ; Panpan Zhang ; Xianxing Jiang ; Rui Wang
• 刊名：The Journal of Organic Chemistry
• 出版年：2012
• 出版时间：November 16, 2012
• 年：2012
• 卷：77
• 期：22
• 页码：10228-10234
• 全文大小：345K
• 年卷期：v.77,no.22(November 16, 2012)
• ISSN：1520-6904

文摘

Herein, the organocatalytic asymmetric Michael/cyclization sequence of 伪-isothiocyanato imides and esters with a variety of unsaturated pyrazolones is presented, in general, affording functionalized spiropyrazolones containing three contiguous stereogenic centers in high levels of diastereo- and enantioselectivity (up to 20:1 dr and 99% ee). Moreover, the current protocol provides a highly efficient and convenient strategy that allows rapid enantioselective construction of diversely spiropyrazolone skeletons with high optical purity.