title: [4+2] or [4+1] Annulation: Changing the Reaction Pathway of a Rhodium-Catalyzed Process by Tuning the Cp Ligand.
abstract: A change in reaction pathway was achieved for the first time by tuning the cyclopentadienyl (Cp) ligand used for the rhodium-catalyzed cyclization of benzamides with conjugated enynones. Depending on the Cp ligand, the reaction pathway switched between [4+2] and [4+1] annulation. Electronic effects turned out to be crucial for the product distribution. The dichotomy was attributed to the alteration of the Lewis acidity of the resultant Cp-bound rhodium species.
authors.affiliation: Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Deajeon, 305-701, Korea.|Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Deajeon, 305-701, Korea.
authors.forename: Seung Youn
authors.initials: SY
authors.lastname: Hong
authors.affiliation: Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Deajeon, 305-701, Korea.|Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Deajeon, 305-701, Korea.
authors.forename: Jisu
authors.initials: J
authors.lastname: Jeong
authors.affiliation: Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Deajeon, 305-701, Korea.|Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Deajeon, 305-701, Korea.
authors.forename: Sukbok
authors.initials: S
authors.lastname: Chang
keywords: annulations; cyclopentadienyl ligands; reaction mechanisms; rhodium catalysis