Coordination attitude of benzothiazole hydrazone in ruthenium(II) complexes: Catalytic applications on direct formation of imines via acceptorless dehydrogenative process

New Ru(II) complexes (1-5) comprising hydrazone of the type [Ru(L1-3)(CO)(PPh3)2]Cl or [Ru(L4-5)H(CO) (PPh3)2] [L1 = (salicyl((2-(benzothiazol-2yl)hydrazono)methylphenol)) (SAL-HBT), L2 = 2-((2-(benzothiazol-2-yl)hydrazono)methyl)-6 methoxyphenol) (VAN-HBT), L3 = naphtyl-2-((2-(benzothiazol-2-yl)hydrazono)meth-ylphenol) (NAP-HBT), L4 = 1-((benzothiazol-2-yl)-2-(furan-2-ylmethylene)hydrazine) (FUR-HBT) or L5 = 1-((benzothiazol-2-yl)-2-(thiophen-2 ylmethylene)hydrazine) (THI-HBT)] have been formulated by reacting [RuHCl(CO)(PPh3)3] with hydrazones in equal molar ratios in ethanol and chloroform medium. The formation of new complexes have been identified by spectral techniques (IR, (1H, 13C &31P) NMR), micro analyses and mass spectrometry. Single crystal XRD study was used to identify solid state structure of the compound 1 and found octahedral geometry around ruthenium metal. The dehydrogenative coupling of alcohol and amine for formation of imines have been performed using the new ruthenium(II) complexes as catalysts.

Automated summary

New Ru(II) complexes (1-5) containing hydrazone ligands have been synthesized and characterized by various spectroscopic and analytical techniques. The crystal structure of compound 1 was determined to have an octahedral geometry around the ruthenium metal. These complexes were also found to be efficient catalysts for the dehydrogenative coupling of alcohols and amines to form imines.