title: Palladium-Catalyzed Hydrohalogenation of 1,6-Enynes: Hydrogen Halide Salts and Alkyl Halides as Convenient HX Surrogates.
abstract: Difficulties associated with handling H2and CO in metal-catalyzed processes have led to the development of chemical surrogates to these species. Despite many successful examples using this strategy, the application of convenient hydrogen halide (HX) surrogates in catalysis has lagged behind considerably. We now report the use of ammonium halides as HX surrogates to accomplish a Pd-catalyzed hydrohalogenation of enynes. These safe and practical salts avoid many drawbacks associated with traditional HX sources including toxicity and corrosiveness. Experimental and computational studies support a reaction mechanism involving a crucial E-to-Z vinyl-Pd isomerization and a carbon-halogen bond-forming reductive elimination. Furthermore, rare examples of C(sp3)-Br and -Cl reductive elimination from Pd(II) as well as transfer hydroiodination using 1-iodobutane as an alternate HI surrogate are also presented.
authors.affiliation: Davenport Research Laboratories, Department of Chemistry, University of Toronto , Toronto, Ontario M5S 3H6, Canada.
authors.forename: David A
authors.identifier: 0000-0001-9867-9178
authors.initials: DA
authors.lastname: Petrone
authors.affiliation: Davenport Research Laboratories, Department of Chemistry, University of Toronto , Toronto, Ontario M5S 3H6, Canada.
authors.forename: Ivan
authors.identifier: 0000-0001-8110-6218
authors.initials: I
authors.lastname: Franzoni
authors.affiliation: Davenport Research Laboratories, Department of Chemistry, University of Toronto , Toronto, Ontario M5S 3H6, Canada.
authors.forename: Juntao
authors.initials: J
authors.lastname: Ye
authors.affiliation: Davenport Research Laboratories, Department of Chemistry, University of Toronto , Toronto, Ontario M5S 3H6, Canada.
authors.forename: José F
authors.initials: JF
authors.lastname: Rodríguez
authors.affiliation: Department of Organic Chemistry, University of Geneva , 30 Quai Ernest Ansermet, 1211 Geneva, Switzerland.
authors.forename: Amalia I
authors.initials: AI
authors.lastname: Poblador-Bahamonde
authors.affiliation: Davenport Research Laboratories, Department of Chemistry, University of Toronto , Toronto, Ontario M5S 3H6, Canada.
authors.forename: Mark
authors.initials: M
authors.lastname: Lautens