171196-18-2Relevant academic research and scientific papers
Thiono, Selenothiono, and Dithiocarboxylic Ester Complexes from Pentacarbonyl(thiobenzaldehyde)tungsten and ?-Donor Substituted Alkynes and Decomplexation of the Esters
Fischer, Helmut,Treier, Kornelia,Troll, Carsten
, p. 883 - 890 (2007/10/02)
Pentacarbonyltungsten-coordinated thiobenzaldehyde, > (1), reacts with 1-methylthio-1-propyne, 1-ethylseleno-1-propyne, and alkoxyethynes by insertion of the CC into the S=C bond to form in a highly regio- and stereoselective manner the α,β-unsaturated dithio, selenothiono, and thionocarboxylic ester complexes (E)(C=C)1-S=C(XR')C(R)=C(Ph)H>> (3) (R = Me: XR' = SMe (a), SeEt (b); R = H: XR' = OEt (c), O-t-Bu (d)).The analogous reaction of 1 with bis(alkylthio)ethynes affords mixtures of the (E) and (Z)(C=C) isomers of 1-S=C(SR)C(SR)=C(Ph)H>> (6) a), t-Bu (b)>.The Z isomers are the initially formed products.Formation of (Z)-6 is followed by Z -> E isomerization until an equilibrium is obtained.For R = t-Bu isomerization is significantly faster than for R = Me.The dithio and thiono ester ligands can be cleaved intact from the metal by treatment with Br as shown by the examples of 3a, 3c, and 6a.Complex 3c has been characterized by an X-ray structural analysis. - Keywords: Thioaldehyde complexes / Dithioester complexes / Selenothiono ester complexes
