title: Sequential Pd(II)-Pd(0) catalysis for the rapid synthesis of coumarins.
abstract: Electrophilic palladium-catalyzed cycloisomerization of brominated aryl propiolates produces brominated coumarins. The brominated coumarins can be diversified by reduction of the Pd(II) catalyst to Pd(0) followed by Suzuki, Sonogashira, Heck, or Hartwig-Buchwald coupling. Thus, a single loading of precatalyst can be used to conduct sequential reactions, allowing the synthesis of functionalized coumarins. Extension of this methodology toward the synthesis of coumarin libraries is discussed.
authors.affiliation: Department of Chemistry, 1251 Wescoe Hall Drive, 2010 Malott Hall, University of Kansas, Lawrence, Kansas 66045-7582, USA.
authors.forename: Kelin
authors.initials: K
authors.lastname: Li
authors.forename: Yibin
authors.initials: Y
authors.lastname: Zeng
authors.forename: Ben
authors.initials: B
authors.lastname: Neuenswander
authors.forename: Jon A
authors.initials: JA
authors.lastname: Tunge
mesh_terms: D001966:Bromine / Q000737:chemistry; D002384:Catalysis; D003374:Coumarins / Q000138:chemical synthesis* / Q000737:chemistry*; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry*
chemical_list: D003374:Coumarins; D010165:Palladium; D001966:Bromine