I2-DMSO-H2O: A Metal-Free Combination System for the Oxidative Addition of Alkynes to Access (E)-α-Iodo-β-methylsulfonylalkenes.

A simple and green reaction was discovered for iodization-methylsulfoxidation of alkynes to access (E)-α-iodo-β-methylsulfonylalkenes. This is the first report for the synthesis of iodovinyl methylsulfones by employing alkynes to react with molecular iodine (I2), dimethyl sulfoxide (DMSO), and H2O. Additionally, this protocol represents a new avenue for utilizing DMSO as the source of the -SO2Me group and H2O as the "O" source for the construction of the -SO2Me group from DMSO, which is a valuable finding.