Ozols K,
Jang Y.-S,
Cramer N.
* École Polytechnique Fédérale de Lausanne, Switzerland
Chiral Cyclopentadienyl Cobalt(III) Complexes Enable Highly Enantioselective 3d-Metal-Catalyzed
C–H Functionalizations.
J. Am. Chem. Soc. 2019;
141: 5675-5680
Key words
cobalt catalysis - C–H functionalization - chiral cyclopentadienyl ligands
Significance
This work is an important advance in catalytic C–H functionalizations for the following
reasons: (1) it is the first example of asymmetric C–H functionalization using a chiral
Cpx-ligand-bound Co(III) complex; (2) it outperforms competing rhodium-catalyzed methods;
(3) reactions with alkyl alkenes give regioisomeric products opposite to those with
rhodium complexes.
Comment
The authors systematically studied the effect of various substituents on the Cpx ligand in the C–H functionalization of chlorobenzamides, a benchmark for chiral CpRh(III)
catalysis. The presence of the tert-butyl group greatly influences the approach of the olefin, whereas the naphthyl backbone
acts to orient and align the metallocene.
