1402215-58-0Relevant articles and documents
Synthesis of heterodinuclear hemisalen complexes on a hexaarylbenzene scaffold and their application for the cross-pinacol coupling reaction
Miyasaka, Akihiro,Amaya, Toru,Hirao, Toshikazu
, p. 1615 - 1621 (2014/03/21)
Intermolecular cross-pinacol coupling reaction between aliphatic and aromatic aldehydes by using heterodinuclear hemisalen complexes 1cis with vanadium(V) and titanium(IV) on a hexaarylbenzene scaffold is reported. Our ligand design is based on the individual activation of two aldehydes by vanadium and titanium, which are positioned with a suitable space on the rigid scaffold. Ligands such as 1cis were synthesized by Diels-Alder addition and decarbonylation reaction, followed by condensation of dialdehyde 3cis with various aminophenols. The influence of the substituents on the ligands on the pinacol coupling reaction was investigated. As a result, the reductive coupling reaction between aliphatic and aromatic aldehydes by using a catalytic amount of 1cis in the presence of Me3SiCl and Zn provided the corresponding cross-coupled 1,2-diol in good yields with high cross-selectivity. Working together: Dihemisalen ligands on a hexaaryl benzene scaffold were designed and the heterodinuclear complexes 1cis with vanadium(V) and titanium(IV) were synthesized from the corresponding disalicylaldehyde compound (see scheme). By using the heterodinuclear catalysts, the selective intermolecular cross-pinacol coupling reaction between aliphatic and aromatic aldehydes is demonstrated. Copyright
