title: Vinylogous Nicholas reactions in the synthesis of bi- and tricyclic cycloheptynedicobalt complexes.
abstract: The Lewis acid mediated intramolecular Nicholas reactions of allylic acetate enyne-Co2(CO)6 complexes afford cycloheptenyne-Co2(CO)6 complexes in three manifestations. Electron rich aryl substituted alkyne complexes give tricyclic 6,7,x-benzocycloheptenyne complexes, with x = 5, 6, or 7. Allylsilane substituted complexes afford exo methylene bicyclic x,7-cycloheptenyne complexes (x = 6,7). The allyl acetate function may also be replaced by a benzylic acetate, to afford dibenzocycloheptyne-Co2(CO)6 complexes. Following reductive complexation, the methodology may be applied to the synthesis of the icetexane diterpene carbon framework.
authors.affiliation: Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada. jgreen@uwindsor.ca.
authors.forename: Izabela
authors.initials: I
authors.lastname: Kolodziej
authors.forename: James R
authors.initials: JR
authors.lastname: Green