Asymmetric C–H Activation for the Synthesis of P- and Axially Chiral Biaryl Phosphine Oxides by an Achiral CpIr Catalyst with Chiral Carboxylic Amide

The catalytic synthesis of P- and axially chiral biaryl phosphine oxides was realized via the Cp*Ir-catalyzed asymmetric C–H coupling of tertiary substituted phosphine oxides with diarylacetylenes. The chiral carboxylic amides were used to control the stereoselectivity in the C–H activation, enabling the construction of chiral phosphine oxides with up to 96% ee. Transformation of the products into chiral trivalent phosphine ligands has also been demonstrated.