Aerobic Oxidation of Secondary Alcohols with Nitric Acid and Iron(III) Chloride as Catalysts in Fluorinated Alcohol

Abstract

Fluorinated alcohols as solvents strongly influence and direct chemical reaction through donation of strong hydrogen bonds while being weak acceptors. We used 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) as the activating solvent for a nitric acid and FeCl 3 -catalyzed aerobic oxidation of secondary alcohols to ketones. Reaction proceeded selectively with excellent yields with no reaction on the primary alcohol group. Oxidation of benzyl alcohols proceeds selectively to aldehydes with only HNO 3 as the catalyst, while reaction on tertiary alcohols proceeds through dehydration and dimerization. A mechanistic study showed in situ formation of NOCl that converts alcohol into alkyl nitrite, which in the presence of Fe 3+ ions and fluorinated alcohol decomposes into ketone. The study indicates that iron(III) acts also as the single-electron transfer catalyst in regeneration of NOCl reactive species.

Oxidative cleavage of C–C double bond in cinnamic acids with hydrogen peroxide catalysed by vanadium(v) oxide

“…Only when DME was used as a solvent was the further oxidation of vanillin 2a to vanillic acid 3a sufficiently slow to allow for the selective formation of vanillin 2a. Fluorinated alcohols are activating solvents for oxidations, 47,48 and the use of TFE resulted in Table 1 The effect of the catalyst structure on the oxidative cleavage of the C-C double bond in ferulic acid 1a with H the complete conversion of 1a to benzoquinone 4a, which was isolated in an 84% yield (Table 2, entry 4).…”

Boosting Aerobic Oxidation of Alcohols via Synergistic Effect between TEMPO and a Composite Fe3O4/Cu-BDC/GO Nanocatalyst

“…Recently, copper­(II) complexes combined with TEMPO radicals , have been proved to have an excellent catalytic performance for selective aerobic oxidation of alcohols. Besides this, benefitting from the potential catalytic sites offered by metal complexes and nanoparticles (NPs), the performance of heterogeneous catalysts could even outperform the corresponding homogeneous counterparts because of the synergetic effect. , Although these methods can circumvent many disadvantages of homogeneous catalysis, typical problems such as a low immobilization capacity, metal leaching, poor catalytic activity and selectivity, etc. still persist. , …”

Ferrocenium Ions as Catalysts: Decomposition Studies and Counteranion Influence on Catalytic Activity

“…30 It has a high ionizing power, is a good hydrogen bond donor, 31,32 is a poor hydrogen bond acceptor, is very polar, and is not very nucleophilic. 33 HFIP can aid in dissolving salts that are otherwise insoluble in organic solvents. Furthermore, it stabilizes potential carbocation intermediates.…”