Anion exchange resins alcohol oxidation

In the three-step process acetone first undergoes a Uquid-phase alkah-cataly2ed condensation to form diacetone alcohol. Many alkaU metal oxides, metal hydroxides (eg, sodium, barium, potassium, magnesium, and lanthanium), and anion-exchange resins are described in the Uterature as suitable catalysts. The selectivity to diacetone alcohol is typicaUy 90—95 wt % (64). In the second step diacetone alcohol is dehydrated to mesityl oxide over an acid catalyst such as phosphoric or sulfuric acid. The reaction takes place at 95—130°C and selectivity to mesityl oxide is 80—85 wt % (64). A one-step conversion of acetone to mesityl oxide is also possible. 

Such oxometal catalysts can also be immobilized as anions on anion exchange resins as reported recently by Kurusu and Masuyama51 who used tetrabromo-oxomolybdate(V) bound to a tetraalkylammonium-containing styrene/divinylbenzene copolymer as a catalyst for the epoxidation of olefins and oxidation of alcohols with TBHP. 

POMs can he immobilized onto anion-exchange resins and surface-modified metal oxides with quaternary ammonium cation- or amino-functional groups via anion-exchange. Jacobs and coworkers tethered Venturello s catalyst [P04(W0(02)2)4]3-on a commercially available nitrate-form resin with alkylammonium cations and have carried out the epoxidation of allylic alcohols and terpenes with this supported catalyst [166, 167]. The regio- and diastereoselectivity of the parent homogeneous catalysts were preserved in the supported catalyst. For bulky alkenes, the reactivity of the POM catalyst was superior to that of Ti- 3 zeolite with a large pore size. The catalytic activity of the recycled catalyst was maintained completely after several cycles. 

The Step 6 product was refluxed 16 hours with 45 ml 2 M NaOH, then acidified with 6M HC1, and concentrated. The residue was dissolved in ethyl alcohol, then treated with propylene oxide, whereupon cis and trans isomers were precipitated. The isomers were separated by chromatography using a Spectrum 1X4 anion exchange resin with dilute acetic acid. Both cis and trans products were isolated as colorless crystals after recrystallization from methyl alcohol/water. 

Cainelli, G., Cardillo, G., Orena, M., Sandri, S. Polymer supported reagents. Chromic acid on anion exchange resins. A simple and practical oxidation of alcohols to aldehydes and ketones. J. Am. Chem. Soc. 1976, 98, 6737-6738. 

NITRIC ACID (7697-37-2) A strong acid and oxidizer. Reacts with water or steam, forming toxic and corrosive nitrous fumes. Violent reaction when water is added to concentrated acid. To dilute, always add acid to water heat will be generated. Reacts violently with reducing agents, bases, combustible materials, finely dispersed or powdered metals and metal alloys, acetic anhydride, acetone, acetylene, acrolein, acrylonitrile, alcohols, aliphatic amines, allyl chloride, ammonia, aniline, anion exchange resins, 1,4-benzoquinone diimine,... 

Polymer-supported /eagent. Italian chemists have prepared a supported form of this oxidant by reaction of the Cl" form of an anion exchange resin (Anibcriyst A-26, Amberlyst A-29, Amberlite IRA 400, or Ainberlite 904) in llaO with chromium trioxide to obtain a CrOaH" form of the resin. This polymeric reagent oxidizes primary and secondary alcohols in high yield (usually 85-957o). The chloride form of the resin is regenerated by wash with NaOH and HCI solutions. 

Chromic acid has been bound to commercial anion exchange resins as the CrO H" form by Cainelli et al. (23). This polymeric species was shown to be quite effective in the oxidation of primary and secondary alcohols to aldehydes and ketones in high yield. Overoxidation of aldehydes did not occur. 

Water is usually considered the most environmentally benign solvent however, the poor solubility of bulkier alcohols and molecular oxygen under ambient conditions has limited its application (in the absence of surfactants [25]). Pt nanoparticles supported on a water-soluble anion exchange resin exhibit excellent E-factors (12.8kilo waste per kilo product) in addition to very good activity and selectivity for alcohol oxidation [136]. Similarly, water has been used as solvent for, for example, benzyUc and primary alcohol oxidations over supported or stabilized Pd [137], Pt [138], and Au [139] clusters. 

Uranyl sulfate usually appears as a lemon-yellow trihydrate (UO2SO4 3H2O) with a density of 3.28 g cm" and is very soluble in 5 parts of water and 25 parts of alcohol. In geochemistry, oxidation of snlfldes would lead to formation of the sulfate, mainly in an acidic environment where carbonates are not present and cause precipitation of uranium. Uranyl sulfate plays a major role in ore processing as it is readily absorbed on anion-exchange resins and may be extracted with amines. As the uranyl sulfate is very stable, the solutions can be heated to elevated temperatures that help dissolve difficult to digest ores. 

Numerous types of basic heterogeneous catalysts, such as alkahne earth metal oxide, anion exchange resins and alkali metal compounds supported on alumina or zeolite can catalyze various chemical reactions such as isomerization, aldol, Michael, and Knoevenagel condensation, oxidation and transesterification [1], Today considerable attention is devoted to the production of biodiesel (FAMEs) as an alternative for petroleum-derived diesel fuel. Biodiesel is synthesized by direct transesterification of vegetable oil or animal fat with a short-chain alcohol, viz. methanol, ethanol, and isopropanol in presence of an acid, base or enzymatic catalyst [2], Considering the advantages of solid base catalysts, for easy separation and recovery, reduced corrosion and environmental acceptance [1], many studies have been conducted on basic heterogeneous catalysts development for biodiesel production [3-13],... 

Immobilized TEMPO has been used for the one-pot oxidation of alcohols to carboxylic acids as well.26 For this purpose TEMPO resin 1 was combined with two ion-exchange resins loaded with chlorite anions and hydrogen phosphate in the presence of catalytic amounts of potassium bromide and sodium hypochlorite in solution. The reaction required work-up for the removal of salts, but tolerated several protecting schemes and afforded pure products in good to excellent yields. The reaction is initiated by catalytic TEMPO oxidation of alcohols to aldehydes driven by dissolved hypochlorite followed by oxidation to the carboxylic acids effected by chlorite. 

Moffat oxidation of amino alcohols with EDC(HCl)/DMSO excess EDO and the formed corresponding urea HC1 cation exchange resin anion exchange resincl [20]... 

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