Iron halide-mediated regio- and stereoselective halosulfonylation of terminal alkynes with sulfonylhydrazides: synthesis of (E)-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 of TBHP, allowing the regio- and stereoselective generation of (E)-β-chloro and bromo vinylsulfones.