title: Chiral and achiral phosphine derivatives of alkylidyne tricobalt carbonyl clusters as catalyst precursors for (asymmetric) inter- and intramolecular Pauson-Khand reactions.
abstract: Phosphine derivatives of alkylidyne tricobalt carbonyl clusters have been tested as catalysts/catalyst precursors in intermolecular and (asymmetric) intramolecular Pauson-Khand reactions. A number of new phosphine derivatives of the tricobalt alkylidyne clusters [Co3(micro3-CR)(CO)9] (R = H, CO2Et) were prepared and characterised. The clusters [Co3(micro3-CR)(CO)9-x(PR'3)x] (PR'3 = achiral or chiral monodentate phosphine, x = 1-3) and [Co3(micro3-CR)(CO)7)(P-P)] (P-P = chiral diphosphine; 1,1'- and 1,2-structural isomers) were assayed as catalysts for intermolecular and (asymmetric) intramolecular Pauson-Khand reactions. The phosphine-substituted tricobalt clusters proved to be viable catalysts/catalyst precursors that gave moderate to very good product yields (up to approximately 90%), but the enantiomeric excesses were too low for the clusters to be of practical use in the asymmetric reactions.
authors.affiliation: Inorganic Chemistry Research Group, Chemical Physics, Center for Chemistry and Chemical Engineering, Lund University, Box 124, SE-221 00, Lund, Sweden.
authors.forename: Viktor
authors.initials: V
authors.lastname: Moberg
authors.forename: M Abdul
authors.initials: MA
authors.lastname: Mottalib
authors.forename: Désirée
authors.initials: D
authors.lastname: Sauer
authors.forename: Yulia
authors.initials: Y
authors.lastname: Poplavskaya
authors.forename: Donald C
authors.initials: DC
authors.lastname: Craig
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Colbran
authors.forename: Antony J
authors.initials: AJ
authors.lastname: Deeming
authors.forename: Ebbe
authors.initials: E
authors.lastname: Nordlander