Ni-Catalyzed Alkenylation of Ketone Enolates under Mild Conditions: Catalyst Identification and Optimization
2015 (English)In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 137, no 22, 7019-7022 p.Article in journal (Refereed) Published
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 degrees 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.
Place, publisher, year, edition, pages
2015. Vol. 137, no 22, 7019-7022 p.
IdentifiersURN: urn:nbn:se:uu:diva-258345DOI: 10.1021/jacs.5b02945ISI: 000356322300012PubMedID: 26024472OAI: oai:DiVA.org:uu-258345DiVA: diva2:841516