Lewis Acidic PSbP Pincer Ligand in Pt-Catalyzed 1,6-Enyne Cycloisomerization: A Theoretical Study.

The progressively improved heterobimetallic antimony transition metal complex PSbP-Pt (I1) provides superior activity in catalyzed 1,6-enyne cycloisomerization. Our DFT calculations demonstrate that the noninnocent character of the antimony ligand enhances the self-activation of the catalyst precursor through a substrate-aided intramolecular chloride migration, which triggers subsequent reaction. Designed alternative redox noninnocent active species with strong electron-withdrawing groups also show promising catalytic ability due to an electron-deficient antimony ligand, which lowers the typical reaction barrier for the cycloisomerization of 1,6-enyne.