Pretransmetalation Intermediates in Suzuki–Miyaura C–C and Carbonylative Cross-Couplings: Synthesis and Structural Authentication of Aryl- and Aroylnickel(II) Boronates

Covalently tethering a supporting ligand to a boron nucleophile
allowed typically elusive, kinetically unstable Suzuki–Miyaura
(SM) pretransmetalation species to be tamed. This strategy enabled
the synthesis and X-ray crystallographic characterization of an organonickel(II)
boronate pretransmetalation intermediate. Performing reactions in
the presence of carbon monoxide delivered pretransmetalation intermediates
in carbonylative SM reactions–aroylmetal boronates. This enabled
the X-ray crystal structure of an aroylnickel(II) boronate (and an
aroylpalladium(II) boronate) to be secured.