thiosulfonyl

Thiosulfonyl is a term used to describe a functional motif in organosulfur chemistry that consists of a sulfonyl group (SO2) bonded to a sulfur atom, generating a thiosulfonyl linkage. The general structural representation is R-SO2-S-R', where the sulfonyl sulfur is connected to another sulfur atom, and R and R' can be various carbon-based substituents. Compounds containing this motif are commonly referred to as thiosulfonates when the second substituent is an organic group, or as thiosulfonyl chlorides when the sulfur bears a leaving group such as Cl.

Preparation and common derivatives: Thiosulfonates typically have the form R-SO2-S-R'. A widely used reagent class is thiosulfonyl chlorides, R-SO2-SCl, which can transfer the thiosulfonyl unit to nucleophiles. A practical preparation route involves reacting a thiol (R'-SH) with a sulfonyl chloride (R-SO2Cl) to yield a thiosulfonate and the inorganic byproduct HCl. Other routes include transformations that introduce the sulfonyl and sulfur fragments in a controlled sequence to form the thiosulfonyl linkage.

Reactivity and applications: The thiosulfonyl group presents a relatively electrophilic sulfur-centered fragment within the molecule. The S–S bond can undergo cleavage under various conditions, enabling transfer of the thiosulfonyl unit to nucleophiles or participation in disconnection and bond-forming strategies. Thiosulfonates and thiosulfonyl chlorides are used in organic synthesis as reagents to install the thiosulfonyl motif, and to activate or modify thiol-containing substrates.

Safety and handling: Reagents bearing the thiosulfonyl motif can be moisture-sensitive and may be corrosive or lachrymating. Work in a suitable fume hood with appropriate personal protective equipment.