Metallation reactions. XXXVI. A study on the metallation of (methylthio)- and (methylsulfonyl)thiophenes

✍ Scribed by Claudia Fattuoni; Michele Usai; Maria G. Cabiddu; Enzo Cadoni; Stefania De Montis; Francesca Sotgiu; Salvatore Cabiddu

• Book ID: 102339228
• Publisher: Journal of Heterocyclic Chemistry
• Year: 2007
• Tongue: English
• Weight: 394 KB
• Volume: 44
• Category: Article
• ISSN: 0022-152X
• DOI: 10.1002/jhet.5570440316

✦ Synopsis

Abstract

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Methylthio‐ and methylsulfonyl thiophenes were polymetallated by n‐buthyllithium and superbase (LICKOR) in one‐step. 2‐(Methylthio)thiophene was bimetallated in 5 and in alpha to the methylthio sulfur atom by superbase. 3‐(Methylthio)thiophene was bimetallated in both 2 and 5 positions by the organolithium and trimetallated in these two positions and in alpha to the thioethereal sulfur atom by superbase. 3‐(Methylsulfonyl)thiophene was bimetallated in 2 and in alpha to the sulfonyl sulfur atom by the organolithium while the 2‐(methylsulfonyl)thiophene underwent degradation in the same conditions.