| Abstract
| - Electrophilic Pt(II) complexes catalyze efficient hydroaminations of olefins by sulfonamides andweakly basic anilines. Catalysts include the structurally characterized complex (COD)Pt(OTf)2 (1) and theknown dimer [PtCl2(C2H4)]2, activated by AgBF4. Experiments with substituted anilines establish an empiricalpKa cutoff (conjugate acid pKa< 1) for the participation of nitrogen-containing substrates in this catalysis.Arylsulfonamides (conjugate acid pKa ≈ −6) with various para substituents hydroaminate olefins such ascyclohexene in yields greater than 95% at 90 °C. Hydroamination of propylene by p-toluenesulfonamideproceeds with Markovnikov selectivity, suggesting a mechanism that involves olefin activation at Pt. Withnorbornene and p-toluenesulfonamide as the substrates and 1 as the catalyst, intermediate [(COD)Pt(norbornene)2][OTf]2 (3) was identified and characterized by 19F and 195Pt NMR spectroscopies and massspectrometry. Kinetic studies provide the empirical rate law, rate = kobs[Pt][sulfonamide], and are consistentwith a mechanism in which attack of a sulfonamide on the Pt-coordinated olefin is the rate-determiningstep.
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