No abstract

The ruthenium complex [Ru­(OAc)­(a-PC)2]Br (3) containing two abnormal NHC ligands is obtained by reaction of Ru­(OAc)2(PPh3)2 (1) with 1-(2-diphenyl­phosphinoethyl)-3-mesityl­imidazolium bromide in the presence of NaOAc. Complex 3 catalyzes the Oppenauer-type oxidation of a number of alcohols at unrivalled reaction rates reaching TOFs up to 550 000 h–1, at low catalyst loadings (S/C higher than 10 000) and using acetone in stoichiometric amounts. Complex 3 is also highly active in the reverse transfer hydrogenation of several ketones with 2-propanol, displaying TOFs up to 600 000 h–1.

Three novel pyridine functionalized N-heterocyclic silanes, bearing chloride and azide moieties, were synthesized and characterized by NMR spectroscopy ( 1 H, 13 C, 29 Si), mass spectrometry, elemental analysis, and single-crystal XRD. The molecular structures show a comparably strong dative interaction of the pyridine-N with the Si center, formally inducing a penta-coordination arrangement at