title: NMR kinetic studies on the decomposition of beta-amidozinc reagents: optimization of palladium-catalyzed cross-coupling with acid chlorides.
abstract: The decomposition of beta-amidozinc reagent 4 by beta-elimination has been shown to be a unimolecular process in both THF and DMF as solvent, with relative rates of 4:1 at room temperature, and activation parameters have been determined. These results indicate the beta-elimination is a syn-process. NMR experiments reveal that as little as 2 equiv of DMF can have a significant stabilizing influence on reagent 4. Use of a mixture of DMA and toluene as the bulk solvent, in place of DMF, has allowed successful palladium-catalyzed cross-coupling reactions of both 4 and the homologous reagent 5 with acid chlorides to yield unsymmetrical ketones (nine examples).
authors.affiliation: Merck Sharp and Dohme Research Laboratories, Neuroscience Research Park, Terlings Park, Eastwick Road, Harlow, Essex, CM20 2QR, UK.
authors.forename: C S
authors.initials: CS
authors.lastname: Dexter
authors.forename: C
authors.initials: C
authors.lastname: Hunter
authors.forename: R F
authors.initials: RF
authors.lastname: Jackson
authors.forename: J
authors.initials: J
authors.lastname: Elliott
mesh_terms: D000577:Amides / Q000138:chemical synthesis* / Q000737:chemistry; D000596:Amino Acids / Q000138:chemical synthesis / Q000737:chemistry*; D002384:Catalysis; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D010165:Palladium / Q000737:chemistry*
chemical_list: D000577:Amides; D000596:Amino Acids; D007202:Indicators and Reagents; C416963:amidozinc; D010165:Palladium