thioetherrelated

Thioether-related is an adjective used in chemistry to describe compounds, motifs, or reactions that involve thioethers (sulfides) or are closely connected to thioether functionalities. A thioether consists of a sulfur atom bonded to two carbon groups (R–S–R′). They are the sulfur analogs of ethers and differ in reactivity and electronic properties due to sulfur’s larger size and higher polarizability.

Structure and properties: In thioethers, sulfur typically adopts a near-tetrahedral geometry and serves as a soft, two-electron donor in coordination chemistry. The C–S–C bond is longer and weaker than a C–O–C bond, contributing to distinct reactivity. Thioethers are relatively nonpolar, with odors and volatility depending on the substituents. They can be oxidized to sulfoxides (R–S(=O)–R′) and further to sulfones (R–SO2–R′). Methionine is a natural example of a thioether within a biological context.

Synthesis and reactivity: Common routes to thioethers include nucleophilic substitution of alkyl halides by thiolates (Williamson-type synthesis) and transition-metal-catalyzed C–S cross-couplings for aryl and alkyl thioethers. Thioethers can undergo oxidative transformations, desulfurization, or substitution at sulfur under appropriate conditions. They also act as versatile ligands in organometallic and coordination chemistry, owing to their soft donor properties.

Applications and scope: Thioether motifs appear in pharmaceuticals, natural products, and materials. They are used as protective groups, in bioconjugation strategies, and as ligand platforms for catalysts. The term thioether-related is employed to denote compounds or reactions that feature or derive from thioether chemistry, without implying a single, formal chemical subclass.