Oxidations of Acyclic Alkenes

Sickle, Dale E. Van; Mayo, Frank R.; Arluck, Richard M.; Syz, Martin G.

doi:10.1021/ja00980a039

Cited by 72 publications

(16 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Very little allylic alcohol, II, was formed, and the allylic hydroperoxide, III, did not accumulate during this reaction. Allison et al (18) have shown that an allylic (10) w + 02…”

Section: Resultsmentioning

confidence: 99%

“…Commercial interest in olefin oxidation is a result of the value and utility of the products-alcohols, acids, carbonyl compounds, epoxides, etc. Classical radical initiated autoxidation of an olefin is usually unselective and yields various oxidation products (10). It is, however, desirable and often imperative that oxidation be selective to be economically attractive.…”

Section: Oxidation Of Olefinsmentioning

confidence: 99%

See 1 more Smart Citation

Oxidation of Olefins in the Presence of Transition Metal Complexes

Lyons

1974

Advances in Chemistry

View full text Add to dashboard Cite

With certain metal complexes the product profile resulting from olefin oxidation differs greatly from that of classical autoxidation. Reactions carried out in the presence of cer tain metal complexes are highly selective in forming one product or a single set of products. When group VIII metal complexes are used, α,β unsaturated alcohols and ketones predominate. With molybdenum, epoxides are formed in high yield; with vanadium complexes, epoxy alcohols are formed. The oxidation of substituted olefins by the com plexes which we studied proceeds via an allylic hydroper oxide intermediate. The observed products are a function of the selective decomposition of the allylic hydroperoxide by the metal complex. In the decomposition of allylic hydroperoxides the products obtained with a given complex parallel the results of oxidation. Manytransition metal complexes react reversibly with molecular oxygen (1, 2) and with olefins (3, 4, 5). van Gaal et al. (6) recently prepared a group VIII metal complex which contains both oxygen and an olefin in the coordination sphere (Reaction 1).(1) L = PPh; PPh3 64

show abstract

“…Very little allylic alcohol, II, was formed, and the allylic hydroperoxide, III, did not accumulate during this reaction. Allison et al (18) have shown that an allylic (10) w + 02…”

Section: Resultsmentioning

confidence: 99%

Section: Oxidation Of Olefinsmentioning

confidence: 99%

Oxidation of Olefins in the Presence of Transition Metal Complexes

Lyons

1974

Advances in Chemistry

View full text Add to dashboard Cite

show abstract

“…(12) Table I were calculated by using the known rates of oxygen consumption and initiation and by neglecting the last term in eq. (13). The average value is about 3.2X lo-* (sec/M)'j2 at 100°C.…”

Section: B Kinetic Considerationsmentioning

confidence: 91%

The liquid‐phase oxidation of 2,4‐dimethylpentane

Mill

Montorsi

1973

Int J of Chemical Kinetics

View full text Add to dashboard Cite

The initiated oxidation of 2,4dimethylpentane in the neat liquid phase at 100°C with 760 torr 0 gives more than 90% of a mixture of 2,4-dihydroperoxy-2,4-dimethylpentane and 2-hydroperoxy-2,4-dimethyIpentane in a ratio of 7 : 1. The rate of oxidation depends closely on the [initiator]"*, consistent with a mechanism in which chain termination occurs mostly by interactions of two 2-hydroperoxy-2,4-dimethyI-4-pentylperoxy radicals. 2,4-Dimethylpentane oxidizes only one sixth as fast as isobutane at the same rate of initiation at 100°C. In cooxidations of the same hydrocarbons? it is 0.71 as reactive as isobutane toward any of the peroxy radicals involved. 2,4-Dimethylpentane oxidizes 7.5 times a s fast at 125°C as at 50°C for the same rate of initiation, but the ratio of dihydroperoxide to monohydroperoxide increases only from 5 to 7, corresponding to a difference in activation energy between intramolecular and intermolecular abstraction of 1 kcal/mole. The overall activation energy (E, -E1,.J is 10.7 kcal/mole, close to the value of 12 kcal/mole found for isobutane.Ring closure of 2-hydroperoxy-2,4-methyl-4-pentyl radicals to oxetane, not detected during oxidation, was observed when this radical was generated at 100°C in the near-absence of oxygen. The rario of rate constants for oxetane formation and addition of oxygen to the 2,4-dimethv1-2-hydroperoxy-4-pentyl radical is about 5.4X 10-5 M at 100°C. Thus, ring closure to oxetane is too slow to compete with addition of oxygen above -200 torr. At 1 OO"C> '2,3-dimethylbutane gave no evidence of any intramolecular abstraction. However, 2.3-dimethylpentane did give at least 1 2yo 2,4-glycol or hydroxvketone.Absolute values for Ep, E,, k,, k,, and k c were derived.

show abstract

“…Sunflower oil, salmon oil, and poultry fat (50 g) were put in different Erlenmeyer flasks (150 mL), and stored at 50 C with orbital shaking at 120 rpm in an incubator (KS 4000 I control, IKA, USA). The PV measurement of oils was done after 5,8,11,14,18,20,22, 26 days of incubation.…”

Section: Oil Oxidation Assaysmentioning

confidence: 99%

Measurement of Peroxide Values in Oils by Triphenylphosphine/Triphenylphosphine Oxide (TPP/TPPO) Assay Coupled with FTIR‐ATR Spectroscopy: Comparison with Iodometric Titration

Deyrieux

Villeneuve

Baréa

et al. 2018

Euro J Lipid Sci & Tech

View full text Add to dashboard Cite

Hydroperoxides (LOOH) measurement is a common technique to determine the degree of oxidation of oils and fats. Although it appears to have some limitations (time consuming, and uses of toxic solvents as chloroform), the iodometric titration is one of the most common methods. Herein, an alternative method by measuring the oxidation level using Fourier transform infrared (FTIR) with an attenuated total reflectance mode (ATR), based on the stoichiometric conversion of triphenylphosphine (TPP) into triphenylphosphine oxide (TPPO) by hydroperoxides, is proposed. The FTIR‐ATR spectroscopy allows for a simple and accurate detection of the TPPO formed by selective reaction with LOOH, with measurement of its specific adsorption band at 542 cm−1. Calibration is made with TPPO solubilized in butan‐2‐one and covers a range of peroxide values (PV) from ≈2 to ≈800 mEq kg−1. The comparison of the iodometric titration and TPP/TPPO assay is performed with standard hydroperoxides (tert‐butyl hydroperoxide and cumene hydroperoxide). The iodometric titration shows higher PV overestimations in comparison with the TPP/TPPO assay, for both hydroperoxides. An accelerated oxidation of different oils is assessed with the two methods, and the results confirm this observation since higher PV values are measured with the titration method. The TPP/TPPO assay coupled with the ATR‐FTIR spectroscopy appears as a simpler and faster assay, which may limit overestimation and use of toxic solvents, especially suitable for routine analysis of oil and fats. Practical Applications: One of the first indicator of oxidation in oils and fats is the presence of hydroperoxides, therefore, it is important to find a reliable method to assess these oxidation products. One of the most common methods to determine lipid hydroperoxide (LOOH) concentrations is iodometric titration. Although this method is simple to set up, it is labor‐intensive, time consuming, and uses a lot of solvent. TPP/TPPO assay coupled with FTIR‐ATR spectroscopy is a good alternative to the iodometric method since it allows a fast and robust hydroperoxide measurement, with minimal use of organic solvents. This rapid peroxide value determination can be adapted for routine quality control analyses, especially for oxidation in real‐time and accelerated aging assays to evaluate oxidative stability during shelf‐life, for industrial purpose or lab scale experiments. The TPP/TPPO coupled with FTIR‐ATR allows for a fast, simple, reasonably sensitive (adequate for most purposes) and reproducible alternative assay to conventional iodometric titration for peroxide value assessment.

show abstract

Oxidations of Acyclic Alkenes

Cited by 72 publications

References 0 publications

Oxidation of Olefins in the Presence of Transition Metal Complexes

Oxidation of Olefins in the Presence of Transition Metal Complexes

The liquid‐phase oxidation of 2,4‐dimethylpentane

Measurement of Peroxide Values in Oils by Triphenylphosphine/Triphenylphosphine Oxide (TPP/TPPO) Assay Coupled with FTIR‐ATR Spectroscopy: Comparison with Iodometric Titration

Contact Info

Product

Resources

About