Ytterbium-Catalyzed Hydroboration of Aldehydes and Ketones

Abstract

The well-defined heavy rare-earth ytterbium iodide complex <b>1</b> (L₂YbI) has been successfully employed as an efficient catalyst for the hydroboration of a wide range of aldehydes and ketones with pinacolborane (HBpin) at room temperature. The protocol requires low catalyst loadings (0.1–0.5 mol %) and proceeds rapidly (>99% conversion in <10 min). Additionally, catalyst <b>1</b> shows a good functional group tolerance even toward the hydroxyl and amino moieties and displays chemoselective hydroboration of aldehydes over ketones under mild conditions