Aryl and vinyl cyclopropanes through the in situ generation of B-cyclopropyl-9-BBN and its Suzuki–Miyaura coupling

Dihydroboration of propargyl bromide with 9-BBN-H followed by treatment of the adduct with aqueous sodium hydroxide affords the hydroxy(cyclopropyl)borate complex (1), which undergoes efficient palladium-catalyzed cross-coupling to produce a variety of aryl and vinyl cyclopropanes (2) in good to excellent yields.