A Catalytic Diastereoselective Formal [5+2] Cycloaddition Approach to Azepino[1, 2‐a]indoles: Putative Donor–Acceptor Cyclobutanes as Reactive Intermediates1. (22nd October 2014)

• Record Type: Journal Article
• Authors: Shenje, Raynold; Martin, M. Cynthia; France, Stefan
• Is Part Of: Angewandte Chemie. Volume 126:Number 50(2014)
• Page Start: 14127
• Page End: 14131
• Publication Date: 2014-10-22
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201408429
• Languages: English
• ISSNs: 0044-8249

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>A catalytic formal [5+2] cycloaddition approach to the diastereoselective synthesis of azepino[1, 2‐<italic>a</italic>]indoles is reported. The reaction presumably proceeds through a Lewis acid catalyzed formal [2+2] cycloaddition of an alkene with an <italic>N</italic>‐indolyl alkylidene β‐amide ester to form a donor–acceptor cyclobutane intermediate, which subsequently undergoes an intramolecular ring‐opening cyclization. Azepine products are formed in up to 92 % yield with high degrees of diastereoselectivity (up to 34:1 d.r.).</p> </abstract>