Efficient hydrosilylation of carbonyls by zinc alkyl complexes supported by flexible amidophosphinochalcogenide ligands

Abstract

In this report, we describe the synthesis and structural characterization of two zinc alkyl complexes supported by anionic PN-morpholine ligand moieties with the general formula [κ²-{Ph₂P(X)N-(CH₂)₂N(CH₂CH₂)₂O}Zn(C₂H₅)]₂ [X = Se (2a); S (2b)]. Both zinc complexes were fully characterized by ¹H, ¹³C{¹H}, and ³¹P{¹H} NMR spectroscopy, and single-crystal X-ray diffraction analysis was performed to determine their molecular structures in the solid state. Complexes 2a and 2b have dimeric structures comprising an eight-membered intermolecular-metalacyclic ring adopting the most stable chair form. Furthermore, zinc complex 2a demonstrated exceptional catalytic activity for hydrosilylation of a wide range of aldehydes and ketones under mild reaction conditions. Hydrosilylated derivatives were confirmed by ¹H and ¹³C{¹H} NMR spectroscopy.