An iodine-promoted C═C bond cleavage with concomitant decarboxylation and cross-coupling between cinnamic acids and NH-sulfoximines has been developed. This reaction proceeds via selective C═C bond cleavage, followed by decarboxylation and oxidative sulfoximidation. This metal- and base-free protocol involves dioxygen as the source of oxygen, which is facilitated by tert-butyl hydroperoxide (TBHP) as the oxidant affording N-aroylated sulfoximines with good functional group tolerance and good yields.