Ketones in poly

Zhu XX, MacDonald PM, Pulsed-gradient spin-echo NMR measurements of the diffusion coefficients of ketones in poly(methyf methacrylate). Maeromolecules 1992 25, 4345. 

Aroylacetonitriles, condensation with ketones in poly-phosphoric acid, 626 2-Aroyl-a-i/,w-dimethylamino-... 

Selective Electrochemical Fluorination, Scheme 15 Solvent-free electrochemical fluorination of cyclic ketones in poly HF salt... 

Polyarylether Ketones. The aromatic polyether ketones are tme thermoplastics. Although several are commercially available, two resins in particular, poly ether ether ketone [31694-16-3] (PEEK) from ICI and poly ether ketone ketone (PEKK) from Du Pont, have received most of the attention. PEEK was first synthesized in 1981 (20) and has been well studied it is the subject of numerous papers because of its potential use in high performance aircraft. Tough, semicrystalline PEEK is prepared by the condensation of bis(4-fiuorophenyl) ketone with the potassium salt of bis(4-hydroxyphenyl) ketone in a diaryl sulfone solvent, such as diphenyl sulfone. The choice of solvent is critical other solvents, such as Hquid HE, promote the reaction but lead to premature low molecular-weight crystals, which do not exhibit sufficient toughness (21). 

Poly(arylene ether ketone) and poly(arylene ether sulfone) were also tried to be incorporated into the hybrids with silica gel by means of the sol-gel procedure [19, 20], For example, triethoxysilyl-terminated organic polymer was subjected to co-hydrolysis with tetraethoxysilane. A systematic change in mechanical and physical properties of the hybrid glass has been found with the content of organic polymer and the annealing temperatures. 

A wide variety of high-performance polymeric materials have been synthesized by incorporating thermally stable moieties such as sulfone, ketone, or aryl or alkyl phosphine oxide in addition to the ether linkage in poly(arylene ether)s. 

Bicakci, E., Zhou, X. and Cakmak, M., Phase and uniaxial deformation behavior of ternary blends of poly(ethylene naphthalate), poly(ether imide) and poly(ether ether ketone), in Proceedings of the 55th SPE ANTEC 97 Conference, May 5-8, 1997, Toronto, ON, Canada, Society of Plastics Engineers, Brookfield, CT, 1997, Vol. 2, pp. 1593-1599. 

Benzyl alcohol can be smoothly converted to benzaldehyde by electrochemi-cally recycled BrO as an oxidizing catalyst in an emulsion system prepared from a mixture of water, amyl acetate, and 2% BU4NHSO4 [60]. A different hypobromite reagent is provided by an electrochemical oxidation of a cross-linked poly-4-vinylpyridine in an MeCN-H20-HBr-(Pt) system [61]. Secondary alcohols can be oxidized by this method to give ketones in high yields. The electrooxidation of A-monoalkyltosylamides (42) in a two-phase system consisting of cyclohexane... 

Another concern for polystyrene- and some aromatic-based PEMs is hydrolysis of fhe sulfonic acid group from aromatic rings as well as hydrolytic cleavage of polymer backbone under fuel cell conditions for aromafic polymers including polyimides, poly(arylene ethers), poly(ether ketones), and poly(ether sulfones). It is well known that the sulfonation of aromafic rings is a reversible process especially at low pH and at elevated temperature (Scheme 3.3). The reversibility of sulfonation, for example, is used in fhe preparafion of trinitrotoluene or picric acid. Por the simplest membrane of the class of arylsulfonic acids (i.e., benzenesulfonic acid), fhe reacfion occurs upon freatment with a stream of superheated steam at 180°C.i ... 

Wholly aromatic polymers are thought to be one of the more promising routes to high performance PEMs because of their availability, processability, wide variety of chemical compositions, and anticipated stability in the fuel cell environment. Specifically, poly(arylene ether) materials such as poly-(arylene ether ether ketone) (PEEK), poly(arylene ether sulfone), and their derivatives are the focus of many investigations, and the synthesis of these materials has been widely reported.This family of copolymers is attractive for use in PEMs because of their well-known oxidative and hydrolytic stability under harsh conditions and because many different chemical structures, including partially fluorinated materials, are possible, as shown in Figure 8. Introduction of active proton exchange sites to poly-(arylene ether) s has been accomplished by both a polymer postmodification approach and direct co-... 

One of the first attempts to extend polymer-assisted epoxidations to asymmetric variants were disclosed by Sherrington et al. The group employed chiral poly(tartrate ester) hgands in Sharpless epoxidations utilizing Ti(OiPr)4 and tBuOOH. However, yields and degree of stereoselection were only moderate [76]. In contrast to most concepts, Pu and coworkers applied chiral polymers, namely polymeric binaphthyl zinc to effect the asymmetric epoxidation of a,/9-unsaturated ketones in the presence of terPbutyl hydroperoxide (Scheme 4.11). 

The direct electrochemical oxidation of aliphatic alcohols occurs at potentials which are much more positive than 2.0 V w. SCE. Therefore, the indirect electrolysis plays a very important role in this case. Using KI or NaBr as redox catalysts those oxidations can be performed already at 0.6 V vs. SCE. Primary alcohols are transformed to esters while secondary alcohols yield ketones In the case of KI, the iodo cation is supposed to be the active species. Using the polymer bound mediator poly-4-vinyl-pyridine hydrobromide, it is possible to oxidize secondary hydroxyl groups selectively in the presence of primary ones (Table 4, No. 40) The double mediator system RuOJCU, already mentioned above (Eq. (29)), can also be used effectively Another double mediator system... 

CD are very rigid molecules and polyrotaxanes derived from them are expected to be more rigid than the starting backbone. Poly(methyl methacrylate side chain rotaxane) 56 had a Tg 20°C higher than the backbone itself. The same observation was also seen in side chain poly(ether ketone) and poly(ether sulfone) systems [96-102]. 

Benzene derivatives with two nucleofuges have been used in the preparation of polymeric materials with varying degrees of success. Poly(l,4-phenylene sulfide) has been prepared by condensation of p-di-chlorobenzene with sodium sulfide,99,100 and in a related process, diazonium ions have been shown to initiate the polymerization of p-halobenzenethiolate ions.101 In a preliminary study, poorly characterized polymers were obtained from reaction of equimolar amounts of p-dihalobenzenes and the enolate ions from ketones in the presence of excess base. When an excess of the ketone enolates was used, the normal p-disubstituted derivatives were formed.102... 

An estimation based on NMR data showed that the route 1 comprises 95% and route 2 only 5% of the total carboxidation rate. These data are dose to the carboxidation results of 2-butene, for which the non-deavage route was found to be 92% and cleavage route 8% [173]. However, in distinction to the individual alkene, where the cleavage route only slightly decreases the selectivity for ketone, in the case of poly-BD, as we shall see below, this route may have dramatic consequences even at a 5% contribution. 

Wu JC, Stubbe J, Kozarich JW (1985b) Mechanism of bleomycin evidence for 4 -ketone formation in poly(dA-dU) associated exclusively with base release. Biochemistry 24 7569-7573 Wu LJ, Randers-Pehrson G, Xu A, Waldren CA, Yu Z, Yu Z, Hei TK (1999) Targeted cytoplasmic irradiation with alpha particles induces mutations in mammalian cells. Proc Nat Acad Sci USA... 

Cyclopenta[2, l -k 3,4-l/]d ithiophen-4-one 581 was considered as a first approximation to it. Ketone 581 displays its lowest n n transition at max = 472 nm (s = 1250). Upon electropolymerization, this long wavelength absorption shifts to 740 nm in the neutral polymer, a red shift of > 200 nm compared to PT. A strong absorption at 425 nm is also present in poly-581. If we assume that the lower energy absorption in neutral poly-581 is derived primarily from the aromatic HOMO-LUMO transition, and the higher energy transition arises between some deeper level and the LUMO. The Egap is < 1.2 eV. 

A new active-iron reducing system - iron(II) chloride tetrahydrate-excess lithium powder-5 mol% 4,4 -di-f-butylbiphenyl in THF - reduces ketones and imines.326 (g) Mono- and poly-cyclic ketones in particular are reduced with good to excellent ee. 

He J, Wu T, Jiang T et al (2008) Aerobic oxidation of secondary alcohols to ketones catalyzed by cobalt(II)/ZnO in poly(ethylene glycol)/C02 system. Catal Commun 9(13) 2239-2243... 

The Friedlander annulation is one of the most straightforward approaches towards poly-substituted quinolines. Thus, a 22-membered library of quinolines was synthesized in a TsOH-catalyzed cyclocondensation-dehydration of 2-aminoaryl ketones and 2-aminoarylaldehydes with ketones in a household microwave oven (with power control) under solvent-free conditions [112]. It was observed that the Friedlander reaction occurred readily also in an oil-bath (at 100 °C). To compare the conventional and dielectric heating conditions precisely, a purpose-built monomode microwave system with temperature control was employed instead of the household oven. The experiments at 100 °C under otherwise identical conditions demonstrated that the dielectric heating protocol was only slightly faster. Products were isolated by a simple precipitation-neutralization sequence (in the case of solid products) or neutralization-extraction for oily or low melting point products (Scheme 43). 

Fig. 10.4. Separation of three types of ketones in 50 mM Tris-HCl buffer, pH 7.3 as the mobile phase with the poly(TBAAm-co-AMPS)-coated column. Conditions column, 750 mm x 25 pm i.d. (600 mm effective length) mobile phase, 50 mM Tris-HCl buffer, pH 7.3 field strength, 400 V/cm injection, 12 kV for 1 s at the side of the anode detection wavelength, 254 nm. Peak identification 1, acetone 2, acetophenone 3, butyrophenone. Reproduced with permission from Sawada and Jinno [11].

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