Asymmetric Synthesis of Spiropyrazolones through Phosphine‐Catalyzed [4+1] Annulation1. Issue 22 (15th April 2014)

• Record Type: Journal Article
• Authors: Han, Xiaoyu; Yao, Weijun; Wang, Tianli; Tan, Yong Ren; Yan, Ziyu; Kwiatkowski, Jacek; Lu, Yixin
• Is Part Of: Angewandte Chemie international edition. Volume 53:Issue 22(2014)
• Page Start: 5643
• Page End: 5647
• Publication Date: 2014-04-15
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201311214
• Languages: English
• ISSNs: 1433-7851

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>An enantioselective synthesis of spiropyrazolones from allenoate‐derived MBH acetates and pyrazolones through a phosphine‐mediated [4+1] annulation process has been developed. Spiropyrazolones were readily prepared in good chemical yields and good to high enantioselectivities. This is the first asymmetric example in which α‐substituted allenoates were utilized as a C₄ synthon for phosphine‐catalyzed [4+1] annulation.</p> </abstract>