(η6-Benzene)Ru(II) half-sandwich complexes of pyrazolated chalcogenoethers for catalytic activation of aldehydes to amides transformation

Publication date: Available online 22 September 2018Source: Journal of Organometallic ChemistryAuthor(s): Kamal Nayan Sharma, Munsaf Ali, Avinash Kumar Srivastava, Raj Kumar JoshiAbstractThe reactions of [(η6-C6H6)RuCl(μ-Cl)]2 with chalcogenoether substituted 1H-pyrazole ligands (L1-L3) in methanol has endowed three novel Ru(II) half-sandwich complexes [(η6-C6H6)RuCl(L)]PF6 (1–3) in high yield under the ambient reaction conditions. The NMR, MS and FT-IR spectral techniques were used to acquaint with their structures. The molecular structures of the complexes 2 and 3 was established with X-ray crystallographic analysis and revealing a pseudo-octahedral half sandwich piano-stool geometry around ruthenium in each case. Complexes 1–3 are thermally robust and found insensitive towards the air and moisture. All the complexes were found catalytically active and produce the excellent conversion of aldehyde to amide (up to 95%). In contrast to previously reported complexes, complexes 1–3 have several advantages in term of catalyst loading, time of reaction, temperature and optimum reaction conditions. Owing to the stronger soft donor properties of the selenium, the complex 2 was found to be more efficient than the sulphur and tellurium analogues.Graphical abstract

Source: Journal of Organometallic Chemistry - October 5, 2018 Category: Chemistry Source Type: research