Pretransmetalation Intermediates in Suzuki-Miyaura Cross-Couplings: Synthesis of C sp 3 -, C sp 2 - and C sp -Organopalladium(II) Boronates.

Organopalladium(II) boronates represent fundamental pretransmetalation intermediates in Suzuki-Miyaura cross-couplings. These species are typically kinetically unstable, making them particularly elusive. In this study, a range of unprecedented, kinetically stable alkyl-, alkenyl-, allenyl-, and alkynylpalladium(II) boronates were prepared from various C sp 3 , C sp 2 , and C sp electrophiles via a simple, general method. The structures of these complexes were secured by X-ray crystallography, and the chemical competence of a number of these intermediates in transmetalation was demonstrated.