Chiral Cyclopentadienyl Ligands in Asymmetric C–H Functionalization.
© 2012 EPFL
Chiral Cyclopentadienyl Ligands as Stereocontrolling Element in Asymmetric C–H Functionalization.
"Metal complexes coordinated by a single cyclopentadienyl (Cp) ligand are widely used, versatile catalysts, but their application to asymmetric reactions has been hindered by the difficulty of designing Cp substituents that effectively bias the coordination sphere. Here, the group of Prof. Nicolai Cramer (Laboratory of Asymmetric Catalysis and Synthesis) report on a class of simple C2-symmetric Cp derivatives that finely control the spatial arrangement of the transiently coordinated reactants around the central metal atom. Rhodium(III) complexes bearing these ligands proved to be highly enantioselective catalysts for directed carbon-hydrogen (C–H) bond functionalizations of hydroxamic acid derivatives."