14741-66-3Relevant academic research and scientific papers
Kinetics and mechanism of the reaction of [Et4N][HFe(CO)4] and alkyl halides. The unexpected formation of acetone
Whitmire, Kenton H.,Lee, T. Randall,Lewis
, p. 987 - 994 (1986)
When [Et4N][HFe(CO)4] is treated with methyl iodide in CH3CN at 25.0 ± 0.2°C, a clean second-order reaction ensues as monitored via the change in the intensity of νCO of the metal carbonyl hydride. In all cases, yields of CH4 were 85-100%. A second-order rate constant (first order in iron and in CH3I) of (1.7 ± 0.1) × 10-2 M-1 s-1 was determined, and activation parameters of Ea = 11.2 ± 1.0 kcal/mol, ΔH? = 10.6 ± 1.0 kcal/mol, and ΔS? = -33 cal/(mol K) were found over the temperature range 15-35°C. The iron product from this reaction is thought to be the unstable Fe(CO)4(NCCH3) , which can also be generated from Fe(CO)5 in CH3CN by irradiation or use of (CH3)3NO. Reaction of iron hydride with 6-bromo-1-hexene produced only 1-hexene and no detectable methylcyclopentane. Reaction with cyclopropylcarbinyl bromide yielded primarily methylcyclopropane and lesser amounts of 1-butene and cis- and trans-2-butene, although evidence is presented to suggest nonrigorously that this is a side reaction. A simple nucleophilic substitution is proposed as the rate-determining step. During this study acetone was detected and confirmed as a reaction product by isotope-labeling studies. A mechanism for this latter observation is discussed.
