Dihydrothiophenes. Synthesis and properties (review)

Multicomponent Reactions in Ionic Liquids

“…Given that most of the synthetic procedures towards sulfur heterocycles suffer from some drawbacks such as low yields, long reaction times, the requirement for harsh reaction conditions, it is not surprising that a number of groups have risen to the challenge and examined the use of ionic liquids as a potential method for enhancing the reaction outcomes whilst increasing the efficiency of the synthesis. [132]- [134] Kumar et al have developed a series of novel amino acid derived functional ionic liquids that facilitated the synthesis of dihydrothiophene and tarcine derivatives in good yield under mild conditions from 2-arylidenemalononitrile, 1,3-thiazolidinedione, aliphatic or aromatic amines were added with ionic liquid [Bz-His(n-propyl) 2 …”

Highly Selective Copper-Catalyzed Ring Expansion of Vinyl Thiiranes: Application to Synthesis of Biotin and the Heterocyclic Core of Plavix

“…Thiophenes and tetrahydrothiophenes are valuable synthetic building blocks which are essential components of a variety of products, ranging from pharmaceuticals to materials. While much effort has been devoted to the synthesis of thiophenes and tetrahydrothiophenes, dihydrothiophenes have received much less attention even though they are more amenable to further functionalization . Despite new methods using olefin metathesis and gold catalysis, the earliest reductive approach by Birch still remains the most common approach .…”