title: Ni-Catalyzed Alkenylation of Ketone Enolates under Mild Conditions: Catalyst Identification and Optimization.
abstract: A procedure for Ni-catalyzed cross-coupling of ketone enolates with alkenyl halides has been developed. Intermolecular coupling of aromatic and aliphatic ketone lithium enolates with a variety of alkenyl halides is achieved in the presence of Ni(cod)2 catalyst (5 mol %), an N-heterocyclic carbene (NHC) ligand, and LiI (10 mol %) at 6-22 °C for 0.5-12 h with yields of up to 90%. During the initial development of this reaction, a misleading result with respect to the actual active catalyst was obtained using commercially available Q-Phos ligand, which was found to contain a trace of Pd metal contaminant sufficient to catalyze the reaction. However, under the final conditions optimized for Ni(cod)2 in the presence of an NHC ligand, Pd was incompetent as a catalyst.
authors.affiliation: †Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States.
authors.forename: Michael
authors.initials: M
authors.lastname: Grigalunas
authors.affiliation: ‡Department of Biochemistry and Organic Chemistry, Uppsala University, Box 576 BMC, SE-751 23 Uppsala, Sweden.
authors.forename: Tobias
authors.initials: T
authors.lastname: Ankner
authors.affiliation: †Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States.|§Pharmaceutical Development, Global Medicines Development, AstraZeneca, Pepparedsleden 1, SE-431 83 Mölndal, Sweden.
authors.forename: Per-Ola
authors.initials: PO
authors.lastname: Norrby
authors.affiliation: †Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States.|∥Lab of Computational Chemistry and Drug Design, School of Chemical Biology and Biotechnology, Peking University, Shenzhen Graduate School, Shenzhen 518055, China.
authors.forename: Olaf
authors.initials: O
authors.lastname: Wiest
authors.affiliation: †Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States.
authors.forename: Paul
authors.initials: P
authors.lastname: Helquist
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D002384:Catalysis; D007659:Ketones / Q000737:chemistry*; D009532:Nickel / Q000737:chemistry*
chemical_list: D000475:Alkenes; D007659:Ketones; D009532:Nickel