title: Palladium-catalyzed carbonylative coupling of (2-azaaryl)methyl anion equivalents with (hetero)aryl bromides.
abstract: Conditions for the palladium-catalyzed coupling of (2-pyridyl)acetones with aryl bromides have been developed. Followed by an acid-promoted deacetylation step, the desired 1-(het)aryl-2-(2-pyridyl)ethanones were obtained in good to excellent yields with high functional group tolerance. Test reactions revealed that both the addition of MgCl2 and a specifically positioned heteroatom in the heteroaromatic ring were crucial for product formation indicating the importance of a chelated intermediate in the reaction mechanism. The reaction conditions proved suitable for a number of 5- and 6-membered heteroaromatic starting materials affording all products in good yields. The utility of the obtained 1-(het)aryl-2-(2-pyridyl)ethanones was demonstrated by the straightforward synthesis of several multiaromatic derivatives in only few additional steps.
authors.affiliation: Interdisciplinary Nanoscience Center (iNANO), Biological and Chemical Engineering, Department of Engineering, Aarhus University, Finlandsgade 22, 8200 Aarhus N (Denmark), Fax: (+45) 4189-3001.
authors.forename: Xavier
authors.initials: X
authors.lastname: Jusseau
authors.forename: Hongfei
authors.initials: H
authors.lastname: Yin
authors.forename: Anders T
authors.initials: AT
authors.lastname: Lindhardt
authors.forename: Troels
authors.initials: T
authors.lastname: Skrydstrup
mesh_terms: D000838:Anions / Q000737:chemistry*; D001372:Aza Compounds / Q000737:chemistry*; D001965:Bromides / Q000737:chemistry*; D002384:Catalysis; D006571:Heterocyclic Compounds / Q000737:chemistry*; D015636:Magnesium Chloride / Q000737:chemistry*; D015394:Molecular Structure; D010165:Palladium
chemical_list: D000838:Anions; D001372:Aza Compounds; D001965:Bromides; D006571:Heterocyclic Compounds; D015636:Magnesium Chloride; D010165:Palladium
keywords: aromatic compounds; carbanions; carbonylation; homogeneous catalysis; pyridine