Creating
a perfect catalyst to operate enzyme-like chiral recognition
has been a long-sought aim. A challenging example in this context
is constructing acyclic all-carbon quaternary stereogenic centers
by transition metal-catalyzed enantioselective C–H activation.
We now report highly enantioselective iridium-catalyzed primary C–H
borylation of α-all-carbon substituted 2,2-dimethyl amides enabled
by a tailor-made chiral bidentate boryl ligand (CBL).
The success of the current transformation is attributed to the CBL/iridium catalyst, which has a confined chiral pocket.
This protocol provides a diverse array of acyclic all-carbon quaternary
stereocenters with excellent enantiocontrol and distinct structural
features. Computational study reveals that steric hindrance of CBL could regulate the type of dominant orbital interaction
between the catalyst and substrate, which is crucial to conferring
high chiral induction.