Catalytic and direct methyl sulfonylation of alkenes and alkynes using a methyl sulfonyl radical generated from a DMSO, dioxygen and copper system

This paper describes an efficient method to β-keto methyl sulfones and ( E )-vinyl methyl sulfones using DMSO as the substrate. The methyl sulfonyl radical generated from DMSO in the presence of catalytic Cu( i ) under O 2 atmosphere is believed to be involved in this reaction. Isotopic labeling and 18 O 2 experiments were performed to investigate the reaction mechanism.