title: Regiochemistry of S-alkyl-substituted alkynes in Pauson-Khand reactions. Is a correlation with X-ray data and charge distribution calculations of the Co(2)(CO)(6)-alkyne complexes possible?
abstract: [reaction: see text] Pauson-Khand reactions (PKR) of RSCtbd1;CR' (6-10) yielded in all cases as the main product the regioisomer with the alkyl-S group disposed alpha to the CO group (16a-22a). Correlation of these results with X-ray data and charge distribution calculations of the corresponding dicobalthexacarbonyl complexes proves that a recently postulated "trans effect" in these complexes is not suitable for predicting the regiochemical outcome of the PKR unambiguously.
authors.affiliation: Organisch-Chemisches Institut, Universität Heidelberg, INF 270, Germany.
authors.forename: J Hilko
authors.initials: JH
authors.lastname: Schulte
authors.forename: Rolf
authors.initials: R
authors.lastname: Gleiter
authors.forename: Frank
authors.initials: F
authors.lastname: Rominger