Methylenecyclopropanecarboxylates and -dicarboxylates, efficient reagents for the [3 + 2] methylenecyclopentane annulation of unactivated and electron-rich alkenes
✍ Scribed by Daniel A. Singleton; Chad C. Huval; Kevin M. Church; E.Scott Priestley
- Publisher
- Elsevier Science
- Year
- 1991
- Tongue
- French
- Weight
- 286 KB
- Volume
- 32
- Category
- Article
- ISSN
- 0040-4039
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✦ Synopsis
The readily available methylenecyclopropanes 1 and 2 efficiently annulate unactivated and electron rich alkenes via a thiyl-radical catalyzed chain cyclization.
We have recently reported the thiyl-radical catalyzed [3 + 21 methylenecyclopentane annulation of alkenes with 2-(phenylsulfonyl)methylenecyclopropanes. 1 This regiospecific annulation works under mild conditions without any need for protecting groups, and does not require the excess of reacting alkene that makes many radical reactions useless with complex alkenes. Furthermore, the product stereochemistry can be modulated by choice of catalyst. 2 We believe that this reaction has advantages over related annulations394