Cooperative Binding of SO₂ under M–O and C–S Bond Formation in a Rhenium(I) Complex with Activated Amino- or Iminopyridine Ligand

Abstract

Metal–ligand cooperative activation of C=O and CN multiple bonds in transition metal complexes with pyridine-based ligands is a currently active field of research. We herein expand the substrate scope to S=O bonds. The anionic complex K [Re(amidopy)(CO)3] readily reacts with a SO2 source to give the sulfinate fac-K[Re(amidopy-OSO)(CO)3] under Re–O and C–S bond formation as a diastereomeric mixture, which shows mutual dynamic interconversion even at ambient temperature. The chemical exchange was studied by 2D 1H 1H EXSY NMR spectroscopy. Activation parameters are obtained via VT 1H NMR and spectral line shape analysis.