The atom‐economic and one‐pot regio‐ and stereoselective addition of sodiumarenesulfinates to either alkynes or alkenes can be achieved with an iron(III) chloride hexahydrate [FeCl3⋅6 H2O] catalytic system to afford β‐haloalkenyl and β‐chloroalkyl sulfones in moderate to good yields.
tetrasubstituted alkynes. Preliminary mechanistic investigations revealed a plausible radicalprocess involving a sulfur‐centered radical intermediate via iron‐mediated homolysis of the ClS bond. The resulting chlorothiolation adducts can be readily transformed to the structurally complex alkenyl sulfides by cross‐coupling reactions. The present reaction can also be applied to the complementary synthesis of the
The three‐component free‐radical carbo‐alkenylation of electron‐richolefins has been studied, varying the substitution pattern in the alkene, in the radical precursor and in the final acceptor. New vinylsulfones were also prepared and their reactivity investigated. The scope and limitations of the process was established, and the reaction mechanism clarified using selected dienes as radical clocks
Iron Halide-Mediated Regio- and Stereoselective Halosulfonylation of Terminal Alkynes with Sulfonylhydrazides: Synthesis of (<i>E</i>)-β-Chloro and Bromo Vinylsulfones
Halosulfonylation of terminal alkynes was achieved with sulfonylhydrazides as the sulfonyl precursor and inexpensive iron halide as halide source in the presence TBHP, allowing the regio- and stereoselective generation of (E)-beta-chloro and bromo vinylsulfones.