Oxidations and Oxidative Couplings Catalyzed by Triazolylidene Ruthenium Complexes

A series of Ru-II(eta(6)-arene) complexes with 1,2,3-triazolylidene ligands have been prepared and fully characterized. The molecular structure of one of the new complexes has been determined by means of X-ray diffractrometry. The new complexes have been tested in a set of catalytic reactions involving alcohols and amines as substrates, including (i) base-free oxidation of benzylic alcohols to benzaldehydes, (ii) homocoupling of amines to form imines, and (iii) oxidative coupling of amines and alcohols to form amides. The results show the high versatility of the catalysts used and illustrate the application potential of 1,2,3-triazolylidene ligands in the design of effective homogeneous catalysts.