Enantioselective Organocatalytic Addition of Nitromethane to Trifluoromethyl Aryl Ketimines Promoted by Electron‐Rich Bifunctional Iminophosphoranes

Thiourea-based iminophosphorane (BIMP) organocatalysts featuring SPhos- or BIDIME phosphine units have been developed and successfully applied in the asymmetric addition of nitromethane to N-Boc-protected trifluoromethyl aryl ketimines. α-Trifluoromethyl β-nitroamines were obtained 40–82% isolated yields 80–95% enantioselectivities. A careful evaluation catalytic activity BIMPs indicates that catalysts derived from combination via Staudinger reaction a chiral 1,2-amino alcohol-derived thiourea-organoazide with electron-rich phosphines, promote aza-Henry on fluorinated ketimines highest enantioselectivity, leading amine tetrasubstituted stereocenter up 95% ee. The was performed also gram scale, without loss enantioselectivity.