title: Preparing alpha,beta-unsaturated Fischer-type carbene complexes via an unforeseen route.
abstract: Four 4-(NH-amino)-1-metalla-1,3-diene carbene complexes, two of which contain novel 4-membered heterometallacycles, formed regioselectively from the reaction of a mixture of [(CH(3))(2)(CH(3)S)S][BF(4)], the acetonitrilium electrophile, CH(3)CNCH(3)(+), and the deprotonated alkoxycarbene complexes, (CO)(5)M=C(OCH(3))CH(2)Li (M = Cr, W). The preferred Z-configurations of the alkoxy and amino groups are determined by strong H-bonding in the products. The metal-carbene bonds in the chelates are shorter by 0.08 A than those in the acyclic compounds.
authors.affiliation: Department of Chemistry and Polymer Science, University of Stellenbosch, Private Bag X1, Matieland, 7602, Stellenbosch, South Africa.
authors.forename: Elzet
authors.initials: E
authors.lastname: Stander
authors.forename: Stephanie
authors.initials: S
authors.lastname: Cronje
authors.forename: Helgard G
authors.initials: HG
authors.lastname: Raubenheimer