Silver-Assisted, Iridium-Catalyzed Allylation of Bis[(pinacolato)boryl]methane Allows the Synthesis of Enantioenriched Homoallylic Organoboronic Esters

Described here is an enantioselective approach of making chiral, beta-substituted homoallylic organoboronic esters. In the presence of (LiOBu)-Bu-t and a catalytic amount of silver salt, commercial bis[(pinacolato)boryl]methane participated in the iridium-catalyzed asymmetric allylation reactions, delivered a CH2B(pin) group, and yielded the title compounds from allylic carbonates. The synthetic utility of the prepared chiral organoboronates was demonstrated by their conversion to other important classes of compounds.