The influence of electronic parameters on the reaction performance of hypervalent iodine(III) reagents in the vicinal diamination of styrene has been investigated. It demonstrates the influence of the relative electron density on the aryl substituent of the hypervalent iodine reagent. In these cases, compounds with donor substituents outperform the corresponding acceptor-substituted systems. In line with this observation, a rapid enantioselective diamination was observed for a preformed chiral bisimidoiodine(III) reagent. For the first time, X-ray structural data could be obtained for an isolated chiral bisimidoiodine(III).