Enantioselective α-C(sp)-H Borylation of Masked Primary Alcohols Enabled by Iridium Catalysis.

Functional group-directed site- and enantioselective C(sp)-H functionalization of alcohols or masked alcohols represents a formidable challenge. We herein report the first example of iridium-catalyzed asymmetric α-C(sp)-H borylation of primary alcohol-derived carbamates by the judicious choice of directing groups. A variety of chiral borylated carbamates were obtained with good to high enantioselectivities. We also demonstrated the synthetic utility by taking advantage of the highly transformable feature of C-B bonds and the leaving ability of carbamates.