Catalytic hydroboration of vinylarenes using a zwitterionic arylspiroboronate ester iridium complex

Addition of B2cat3 (cat = 1,2-O2C6H4) to Ir(acac)(dppb) (1; where dppb = 1,4-bis(diphenylphosphino)butane) gave the novel arylspiroboronate ester iridium complex Ir(η6-catBcat)(dppb) (2), the first example of an iridium compound containing a coordinating [Bcat2]− anion. Complex is a remarkably selective catalyst precursor for the hydroboration of unhindered vinylarenes using pinacolborane.