Germanium(II) and Tin(II) N-Aryloxy-β-Ketoiminate Complexes: Coordination Features and Catalytic Activity in Hydroboration Reactions

Abstract

The hybrid tridentate N-phenoxy-β-ketoiminate ligand (PacNacH₂) is applied for the first time in the synthesis of low-valent Group 14 element derivatives. It enables the preparation and characterization of tin(II) (PacNacSn) and germanium(II) (PacNacGe) compounds being stable under anaerobic and moisture-free conditions. Single crystal X-ray diffraction studies reveals that tin complex PacNacSn exists as a dimer assembled through additional intermolecular Sn–O contacts. In catalytic tests, synthesized tetrylenes exhibit a high catalytic activity in benzaldehyde hydroboration with pinacolborane (HBPin) under mild conditions and with catalyst loadings as low as 0.1 mol %.