Bifunctional Triflylamide-Tethered Cp′Rh and Cp′Ir Complexes: A New Entry for Asymmetric Hydrogenation Catalysts

Abstract

A series of triflylamide-tethered Cp′Rh and Cp′Ir complexes, [η 5:η 1 -(CH 3 ) 4 C 5 (CH 2 ) n NTf]M (M = Rh, Ir, n = 2−4), have been newly prepared and their three-legged piano-stool structure has been characterized. The tethered complexes having the ( R, R )-MsDPEN ligand have been found to promote asymmetric hydrogenation of acetophenone, which indicates that the introduction of a suitable triflylamide tether unit changes their catalytic function from transfer hydrogenation to hydrogenation.