Catalytic Asymmetric Tamura Cycloadditions1. (7th February 2014)

• Record Type: Journal Article
• Authors: Manoni, Francesco; Connon, Stephen J.
• Is Part Of: Angewandte Chemie. Volume 126:Number 10(2014)
• Page Start: 2666
• Page End: 2670
• Publication Date: 2014-02-07
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201309297
• Languages: English
• ISSNs: 0044-8249

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>In the presence of a novel, <italic>tert‐</italic>butyl‐substituted squaramide‐based catalyst, enolizable anhydrides react with alkylidene oxindoles to generate spirooxindole products of significant synthetic interest with excellent enantio‐ and diastereocontrol. The methodology is of wide scope and encompasses both homophthalic and glutaconic anhydride derivatives, which lead to structurally diverse products. Glutaconic acid‐derived anhydrides undergo a clean post‐cyclization decarboxylation process which is not a feature of reactions involving homophthalic acid‐derived anhydrides. The unusual influence of reaction temperature on diastereocontrol has been probed, with reactions occurring at 30 °C and −30 °C delivering products epimeric at one stereocenter only, in near optical purity.</p> </abstract>