Dedicated to Prof. Wolfgang Beck on the occasion of his 90th birthday.A simple and efficient protocol allows the oxidation of the cyclopentadiene derivative 5H-dibenzo[e,h]-dibenzo [3,4 : 6,7] cyclohept [1,2-a]azulene (Cp C H) provide according ketone Cp C O. Comparable to the situation found for Cp C H, the bending of the four annulated six-membered rings defines the C 2 symmetric molecular structure of Cp C O. The cyclopentadienone Cp C O readily reacts with [Ru 3 (CO) 12 ] and [Fe 3 (CO) 12 ] to generate tricarbonyl complexes of the type [(η 4 -Cp C O)M(CO) 3 ]. In contrast to [(η 4 -Cp C O)Ru(CO) 3 ], the tricarbonyliron(0) complex is sensitive to oxygen and moisture. Refluxing [(η 4 -Cp C O)Ru(CO) 3 ] in isopropanol makes the hydrido-bridged complex [((η 4 -Cp C O) 2 H) Ru 2 (CO) 4 H] accessible, an analogue to Shvo's catalyst. Both ruthenium complexes and their ligand Cp C O were characterized spectroscopically and by single crystal x-ray diffraction. The activity of [(η 4 -Cp C O)Ru(CO) 3 ] was investigated for a series of transfer hydrogenation reactions.

The oxidation of a series of fatty alcohols to yield the corresponding aldehydes is performed using RuCl3 ⋅ (H2O)x as a homogeneous catalyst and inexpensive trimethylamine N‐oxide (TMAO) as the oxygen source. The reaction conditions were optimized for both high conversion and high selectivity.