thioetherlinked

Thioetherlinked refers to a molecule in which two carbon-containing fragments are joined by a thioether bridge, typically written as R–S–R'. The thioether linkage consists of a sulfur atom bound to two carbon atoms and is analogous to an ether, with sulfur replacing oxygen.

The C–S–C motif is flexible and relatively nonpolar, contributing conformational mobility to the molecule. Thioethers are generally chemically stable toward hydrolysis but can be selectively oxidized to sulfoxides (R–S(O)–R') or sulfones (R–S(O)2–R'), increasing polarity and altering reactivity. In biological systems, thioether-containing structures occur in various contexts, including the methionine side chain and in cross-linked natural products such as lanthipeptides, where thioether bridges (lanthionine and related motifs) connect cysteine sulfur to dehydroalanine residues.

Natural and synthetic uses of thioether linkages are common. In bioconjugates and medicinal chemistry, thioether linkers provide stable spacers between a drug and a targeting molecule or polymer. They are also employed as flexible linkers in polymers and dendrimers, and as components in lipid-like and small-molecule constructs.

Synthesis of thioether bonds typically proceeds via nucleophilic substitution of a thiolate on an alkyl halide or sulfonate (SN2 thioether formation), or through thiol-ene reactions that add a thiol across a carbon–carbon double bond. Aryl thioethers can be formed by transition-metal-catalyzed cross-couplings of thiols with aryl halides.

Overall, thioetherlinked architectures are valued for their chemical stability, flexibility, and utility as linkers in a range of chemical and biochemical contexts.