title: An Iron-Catalyzed Bond-Making/Bond-Breaking Cascade Merges Cycloisomerization and Cross-Coupling Chemistry.
abstract: Treatment of readily available enynes with alkyl-Grignard reagents in the presence of catalytic amounts of Fe(acac)3 engenders a remarkably facile and efficient reaction cascade that results in the net formation of two new C-C bonds while a C-Z bond in the substrate backbone is broken. Not only does this new manifold lend itself to the extrusion of heteroelements (Z=O, NR), but it can even be used for the cleavage of activated C-C bonds. The reaction likely proceeds via metallacyclic intermediates, the iron center of which gains ate character before reductive elimination occurs. The overall transformation represents a previously unknown merger of cycloisomerization and cross-coupling chemistry. It provides ready access to highly functionalized 1,3-dienes comprising a stereodefined tetrasubstituted alkene unit, which are difficult to make by conventional means.
authors.affiliation: Max-Planck-Institut für Kohlenforschung, 45470, Mülheim/Ruhr, Germany.
authors.forename: Pierre-Georges
authors.initials: PG
authors.lastname: Echeverria
authors.affiliation: Max-Planck-Institut für Kohlenforschung, 45470, Mülheim/Ruhr, Germany. fuerstner@kofo.mpg.de.
authors.forename: Alois
authors.initials: A
authors.lastname: Fürstner
keywords: 1,3-dienes; Grignard reagents; cross-coupling; cycloisomerization; enynes; iron catalysis