Mild complexation protocol for chiral Cp x Rh and Ir complexes suitable for in situ catalysis.

A practical complexation method for chiral cyclopentadienyl (Cpx ) iridium and rhodium complexes is described. The procedure uses the free Cpx H with stable and commercially available rhodium(i) and iridium(i) salts without base or additive. The conditions are mild and do not require the exclusion of air and moisture. A salient feature is the suitability for in situ complexations enhancing the user-friendliness of Cpx ligands in asymmetric catalysis. DFT-calculations confirm an intramolecular proton abstraction pathway by either the bound acetate or methoxide. Furthermore, the superior facial selectivity of the proton abstraction step enabled the development of TMS-containing trisubstituted Cpx ligands which display improved enantioselectivities for the benchmarking dihydroisoquinolone synthesis.