Combination of Rearrangement with Metallic and Organic Catalyses – a Step- and Atom-Economical Approach to α-Spiroactones and -lactams

✍ Scribed by Thomas Boddaert; Yoann Coquerel; Jean Rodriguez

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 878 KB
• Volume: 2011
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/ejoc.201100734

✦ Synopsis

Abstract

A general synthetic route to α‐spirolactones and ‐lactams from 2‐diazo‐1,3‐dicarbonyl compounds, (homo)allylic alcohols or amines and acrylic derivatives, involving a single consecutive reaction consisting of a Wolff rearrangement/α‐oxo ketene trapping/cross metathesis/Michael addition sequence is described. During the consecutive reaction optimization, the organocatalytic activity of N,N‐diaryl‐1,3‐imidazol(in)‐2‐ylidene N‐heterocyclic carbenes (NHCs) in the Michael addition of 1,3‐dicarbonyl compounds was discovered. A conceptually attractive version of the consecutive reaction was then developed, involving the Grubbs–Hoveyda ruthenium‐based precatalyst containing the SIMes [1,3‐bis(2,4,6‐trimethylphenyl)imidazolin‐2‐ylidene] NHC ligand as the source of both the organometallic catalyst of the cross metathesis and the organic catalyst of the intramolecular Michael addition.