title: Chloroform as a hydrogen atom donor in Barton reductive decarboxylation reactions.
abstract: The utility of chloroform as both a solvent and a hydrogen atom donor in Barton reductive decarboxylation of a range of carboxylic acids was recently demonstrated (Ko, E. J. et al. Org. Lett. 2011, 13, 1944). In the present work, a combination of electronic structure calculations, direct dynamics calculations, and experimental studies was carried out to investigate how chloroform acts as a hydrogen atom donor in Barton reductive decarboxylations and to determine the scope of this process. The results from this study show that hydrogen atom transfer from chloroform occurs directly under kinetic control and is aided by a combination of polar effects and quantum mechanical tunneling. Chloroform acts as an effective hydrogen atom donor for primary, secondary, and tertiary alkyl radicals, although significant chlorination was also observed with unstrained tertiary carboxylic acids.
authors.affiliation: ARC Centre of Excellence for Free-Radical Chemistry and Biotechnology, Research School of Chemistry, Australian National University, Canberra, ACT, Australia.
authors.forename: Junming
authors.initials: J
authors.lastname: Ho
authors.forename: Jingjing
authors.initials: J
authors.lastname: Zheng
authors.forename: Rubén
authors.initials: R
authors.lastname: Meana-Pañeda
authors.forename: Donald G
authors.initials: DG
authors.lastname: Truhlar
authors.forename: Eun Jung
authors.initials: EJ
authors.lastname: Ko
authors.forename: G Paul
authors.initials: GP
authors.lastname: Savage
authors.forename: Craig M
authors.initials: CM
authors.lastname: Williams
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Coote
authors.forename: John
authors.initials: J
authors.lastname: Tsanaktsidis
mesh_terms: D002264:Carboxylic Acids / Q000737:chemistry*; D002725:Chloroform / Q000737:chemistry*; D003653:Decarboxylation; D006859:Hydrogen / Q000737:chemistry*; D010084:Oxidation-Reduction; D011789:Quantum Theory; D013816:Thermodynamics
chemical_list: D002264:Carboxylic Acids; D002725:Chloroform; D006859:Hydrogen