Influence of the Ligand Backbone in Pincer Complexes: Indenediide‑, Indolyl‑, and Indenyl-Based SCS Palladium Complexes

A new pincer ligand featuring an
indolyl backbone was prepared
and coordinated to palladium. The properties of related indenediide-,
indenyl-, and indolyl-based complexes have been compared by spectroscopic
and structural means. Modulation of the ligand backbone was shown
to significantly influence the electron density at Pd. Its impact
on catalytic performance has been illustrated in the Pd-catalyzed
imine allylation. The higher the electron density at Pd, the more
active the SCS pincer complex.