Catalytic Enantioselective Primary C–H Borylation for Acyclic All-Carbon Quaternary Stereocenters

Abstract

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 (<b>CBL</b>). The success of the current transformation is attributed to the <b>CBL</b>/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 <b>CBL</b> could regulate the type of dominant orbital interaction between the catalyst and substrate, which is crucial to conferring high chiral induction.