Retardation of β-hydrogen elimination in PNP Pincer complexes of Pd

A series of new alkyl and alkoxide (FPNP)Pd complexes have been synthesized. The alkyls and alkoxides containing β-hydrogens display remarkable thermal stability. Thermal decomposition of (FPNP)PdOEt is very slow in pure C6D6 but is accelerated by the addition of EtOH co-solvent. It is proposed that the β-hydrogen elimination from (FPNP)Pd–OCH2R occurs via dissociation of the alkoxide anion.

The alkyl complexes (PNP)PdR and alkoxide complexes (PNP)PdOR display remarkable thermal stability despite the presence of β-hydrogens. The resistance to β-hydrogen elimination is owing to the rigidity of the PNP ligand blocking the cis coordination sites.Figure optionsDownload as PowerPoint slide