Iridium-Catalyzed, Hydrosilyl-Directed Borylation of Unactivated Alkyl C–H Bonds

We report the iridium-catalyzed borylation of primary and secondary alkyl C–H bonds directed by a Si–H group to form alkylboronate esters site selectively. The reactions occur with high selectivity at primary C–H bonds γ to the hydrosilyl group to form primary alkyl bisboronate esters. In the absence of such primary C–H bonds, the borylation occurs selectively at a secondary C–H bond γ to the hydrosilyl group, and these reactions of secondary C–H bonds occur with high diastereoselectivity. The hydrosilyl-containing alkyl boronate esters formed by this method undergo transformations selectively at the carbon–boron or carbon–silicon bonds of these products under distinct conditions to give the products of amination, oxidation, and arylation