Polymer resin potassium

However, thermolysis of the phosphonium salts (X=+PPh3) leads directly to the indolic products without need of acid catalyst or PPh3, and thus may not proceed via a normal Wittig pathway. Alternatively, Hughes has effected a solid-phase version of this reaction employing a polymer-hound phosphonium salt and potassium tert-butoxide as base <96TL7595>. In this case, the phosphine oxide by-product remains bound to the polymer resin. 

Specialty concrete contains specialized binders such as K silicate, calcium aluminate, sulfur, and oxysulfate or polymer resins. In contrast to conventional construction products, specialty concrete is not based on Portland cement. Instead, specialty concrete is composed of specialty cement such as potassium silicate that is mixed with water, a coarse aggregate such as gravel or crushed stone, and a fine aggregate or sand. 

Ethyl Vinyl Ether. The addition of ethanol to acetylene gives ethyl vinyl ether [104-92-2] (351—355). The vapor-phase reaction is generally mn at 1.38—2.07 MPa (13.6—20.4 atm) and temperatures of 160—180°C with alkaline catalysts such as potassium hydroxide and potassium ethoxide. High molecular weight polymers of ethyl vinyl ether are used for pressure-sensitive adhesives, viscosity-index improvers, coatings and films lower molecular weight polymers are plasticizers and resin modifiers. 

In a more recent study, Wang and coworkers have discussed microwave-assisted Suzuki couplings employing a reusable polymer-supported palladium complex [141]. The supported catalyst was prepared from commercial Merrifield polystyrene resin under ultrasound Bonification. In a typical procedure for biaryl synthesis, 1 mmol of the requisite aryl bromide together with 1.1 equivalents of the phenyl-boronic acid, 2.5 equivalents of potassium carbonate, and 10 mg of the polystyrene-... 

FIGURE 5.10 Synthesis of a polyethyleneglycol-polystyrene graft polymer by etherification of Merrifield resin using potassium tetra(oxyethylene) oxide, followed by extension of the chain by reaction of the potassium salt, which is present as the crown ether.21 In several TentaGel resins, the connecting bond is an ethyl ether that is more acid-stable than the benzyl ether. 

Polymer-supported persulfonic acid was prepared from potassium persulfate and the cation exchange resin P—SO3H in water. The authors reported various applications of this new oxidizing reagent such as epoxidation of olefins, Baeyer-Villiger reaction and cleavage of disulfide and Af-formylamino acids. 

Chemical methods used for the determination of hydroxyl groups or alcoholic constituents in polymers are based on acetylation [16-18], phthalation [18], and reaction with phenyl isocyanate [18,19] or, when two adjacent hydroxy groups are present in the polymers, by reaction with potassium periodate [9,17]. Alcoholic hydroxyl groups may be found in the following polymers (1) poly(ethylene terephthalate) (PET) [20], (2) poly(methyl acrylate), [21], (3) poly(methyl methacrylate) [21], and (4) polyhydric alcohols in hydrolysates of poly(ester) resins [22]. 

Polymer-supported reagent. HMPT supported on a polystyrene-type resin is a catalyst for SN2 reactions5-7 and for reduction of ketones by NaBIi4.7 It also has a marked effect on the alkylation of ethyl acetoacetate with diethyl sulfate. In the presence of solid HMPT the enolales undergo 60 70% O-alkylation. In the absence of HMPT, the lithium enolate does not react and the sodium and potassium enolates undergo C-alkylation (90-100%). There is some difference in the effect of solid and liquid I1MPT The solid HMPT increases the reactivity of the K. enolate more than the liquid form, whereas the reverse is true with the Li enolate.8... 

The reaction of melamine with formaldehyde is a useful one, as the initial product (39) forms a resin on heating. Such condensates are very important polymers (see Section 2.20.6.3 and Chapter 1.11). Melamine and other amino-1,3,5-triazines form salts with aqueous acids. In addition, the amino-1,3,5-triazines form potassium and silver salts (58CRV131). 

The palladium-catalyzed, microwave-assisted conversion of 3-bromopyridine to 3-cyanopyridine using zinc cyanide in dimethylformamide (DMF) has been reported <2000JOC7984>. Substoichiometric quantities of copper or zinc species improve both conversion rate and efficiency of Pd-catalyzed cyanation reactions <1998JOC8224>. A modification of this procedure uses a heterogeneous catalyst prepared from a polymer-supported triphenylphosphine resin and Pd(OAc)2 the nitriles were obtained from halopyridines in high yields <2004TL8895>. The successful cyanation of 3-chloropyridine is observed with potassium cyanide in the presence of palladium catalysts and tetramethylethylenediamine (TMEDA) as a co-catalyst <2001TL6707>. 

A convenient solid of perfluorinated-sulfonic acid can be made readily from DuPont s commercially available Nafion brand ion membrane resins. Powder granules of the 1200-EW polymer, Nafion 501, have been used most frequently in catalytic applications the price in the K+ form of the perfluorosulfonic salt, 501X, was 650/kg in 1981. Because only the potassium salt derivative is commercially available, the salt is converted to the free sulfonic acid by treatment with mineral acid. A standard procedure for the conversion is described below. This procedure also serves to regenerate the resin in various catalytic cycles. 

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