Acid-induced displacement of acetaldehyde from a µ-vinyloxy-triosmium cluster
Abstract
Protonation of the µ-vinyloxy-ligand in [Os3H(µ-OCHCH2)(CO)10] with HX (X = Cl or CF3CO2) leads to the compounds [Os3H(X)(CO)10] with liberation of acetaldehyde (ethanal). Several intermediates including the addition species [Os3H(µ-OCHXCH3)(CO)10](X = Cl or CF3CO2) have been identified (and isolated for X = Cl). These addition compounds readily undergo β-elimination of acetaldehyde. This reaction has been exploited as a synthetic route to the known complexes [Os3H(X)(CO)10](X = Cl, Br, I, CF3CO2′ or OH) and the new compounds from potassium O-ethyl dithiocarbonate and NN-diethyldithiocarbamate, [Os3H(S2COEt)(CO)10](two isomers) and [Os3H(S2CNEt2)(CO)10]. The complex [Os3H(S2CNEt2)(CO)10] undergoes ready decarbonylation to [Os3H(S2CNEt2)(CO)9].