Mechanism insight and scope of PEPPSI-catalyzed cross-coupling reaction between triarylbismuth and arylbromide
Mark:
Scheme 4
Associated context:
Organs usually involve a dissociative mechanism when the initial Pd(0) complex NHC-Pd(0)-Pyr loses the weak ligand 3-chloropyridine.[29] In this hypothesis, the active species would be an NHC-Pd(0) complex. However, this mechanism is not consistent with the crucial rule of PPh3. The first hypothesis would be that a dissociative mechanism will lead to NHC-Pd(0) and that in the presence of Ar3Bi, this last complex will not be stable enough as it has been already demonstrated with Pd(PPh3)4.[30] Therefore this NHC-Pd(0) species requires to be stabilized by an ancillary ligand such as PPh3 via a pool effect (Scheme 4).
