Hydroquinine-catalyzed asymmetric 1,4-hydrophosphination of in situ generated aza-o-quinone methides with H-phosphine oxides†
Abstract
An organocatalytic enantioselective 1,4-hydrophosphination of in situ generated aza-o-quinone methides with H-phosphine oxides has been successfully established in the presence of simple and commercially available hydroquinine. This methodology furnishes an efficient route to a variety of optically active diarylmethyl phosphine oxides in moderate to good yields with good to excellent enantioselectivities. The protocol represents a unique example of asymmetric 1,4-conjugate addition of aza-o-quinone methides via C–P bond formation.