Catalytic Borylation using an Air-Stable Zinc Boryl Reagent: Systematic Access to Elusive Acylboranes

The use of borylzinc reagents in palladium-catalyzed borylation chemistry is described (i.e. a boron analogue of the Negishi coupling), including a one-pot bench-top protocol using an air-and moisture-stable bis(boryl) zinc reagent. The steric/electronic properties of the boryl fragment employed enable a systematic method for accessing acylboranes, a rare class of organoboron species with great potential in chemical synthesis. The reactions proceed under mild conditions, use inexpensive commercial sources of palladium, and demonstrate a remarkable functional-group tolerance.