SIAPhos: Phosphorylated Sulfonimidamides and their Use in Iridium‐Catalyzed Asymmetric Hydrogenations of Sterically Hindered Cyclic Enamides

Phosphorylated sulfonimidamides (SIAPhos) undergo ion exchange reactions with cationic complexes, [Rh(cod) 2 BF 4 ] and [Ir(cod) 2 BarF], or neutral complexes [Rh(cod)Cl] 2 and [Ir(cod)Cl] 2 , leading to unprecedented neutral complexes with P‐N‐S‐N chelates. Use of the resulting neutral iridium complexes in asymmetric hydrogenation reactions of tri‐ and tetrasubstituted enamides leads to products with high enantioselectivities (up to 92% ee ).