Alkyl ester, fluorinated,

Table XII. Effect of Organic Additives (Urea, Silanes, Fluorinated Alkyl esters) on Grafting of Styrene to Polypropylene Initiated by UVa...

Conditions as in Table XII additives used were urea, silane and fluorinated alkyl ester TMPTA (1% v/v) N.S. = no sensitizer. 

The polyimide-perfluoroalkyl ether block copolymers were prepared through the poly(amic alkyl ester) route, where a solution of diester diacyl chloride of PMDA was added to a mixture of ODA and the perfluoroalkyl ether oH-gomer, analogous to the procedure previously described [55]. Toluene was used as a cosolvent together with NMP to improve the solubility of the fluorinated coblock, and the resulting polymers were isolated by precipitation. The charac-... 

Low-valent palladium complex, for example, Pd(0), is readily prepared in situ by reaction of PdCl2(PPh3)2/Zn. This is shown to induce the similar homocoupling polycondensation of metaphenylene 183 at 95 °C in DMF. Fluorinated alkyl esters 180 polymerize smoothly in supercritical CO2 1,4-dichlorophenylene 184 having a keto group also reductively polymerized similarly. 

This method is also useful for enantioselective fluorination of alkyl esters of type 65 (Scheme 3.27, Eq. 1) [78, 79]. The resulting fluoro-organic products 66 are use-... 

One class of such materials is the fluorinated alkyl esters of acrylic and methacrylic acid, a number of which have been prepared [1]. One of these esters, poly(l,l-dihydropentadecafluoro-octyl methacrylate), has a 11 dynes per cm.—less than Teflon TFE or even FEP [4]. Such materials, and others within the general class of unsaturated, appropriately fluorinated, polyesters warrant investigation for use either as thermoplastic hot-melt adhesives, or for cross linking in situ to form rigid thermoset adhesives. The saturated, appropriately fluorinated polyesters also warrant investigation as thermoplastic hot-melt adhesives. 

In 2001, Hitachi, Ltd. discovered that fluorinated alkyl esters, such as methyl perfluorobutyrate (150), can be used as additives in small quantities [145]. 

Chem. Descrip. Fluorinated alkyl ester Ionic Nature Nonionic... 

Particularly alkyl halides which have a perfluoroalkyl group at the /3-position undergo smooth carbonylation. Probably the coordination of fluorine to form a five-membered chelate ring accelerates the reaction. Double carbonylation to give the a-keto amide 915 is possible in Et NH with the fluorine-bearing alkyl iodide 914[769,770]. The ester 917 is obtained by the carbonylation of the /3-perfluoroalkyl iodide 916 in ethanol. 

All lation. In alkylation, the dialkyl sulfates react much faster than do the alkyl haHdes, because the monoalkyl sulfate anion (ROSO ) is more effective as a leaving group than a haHde ion. The high rate is most apparent with small primary alkyl groups, eg, methyl and ethyl. Some leaving groups, such as the fluorinated sulfonate anion, eg, the triflate anion, CF SO, react even faster in ester form (4). Against phenoxide anion, the reaction rate is methyl triflate [333-27-7] dimethyl sulfate methyl toluenesulfonate [23373-38-8] (5). Dialkyl sulfates, as compared to alkyl chlorides, lack chloride ions in their products chloride corrodes and requires the use of a gas instead of a Hquid. The lower sulfates are much less expensive than lower bromides or iodides, and they also alkylate quickly. 

Deep fluorinalion of alkanes, ethers, acid fmlides, esters, alkyl chlorides, most ketones, ketals, orthoesters, and combinations of these functional groups produces principally the perfluonnated analogues (Table 2) Chlorine substituents (or chloro groups) usually survive fluorination... 

During electrochemical fluorination retention of important functional groups or atoms in molecules is essential. Acyl fluorides and chlorides, but not carboxylic acids and anhydrides (which decarboxylate), survive perfluorination to the perfluorinated acid fluorides, albeit with some cyclization in longer chain (>C4) species [73]. Electrochemical fluorination of acetyl fluoride produces perfluoro-acetyl fluoride in 36-45% yields [85]. Electrochemical fluorination of octanoyl chloride results in perfluorinated cyclic ethers as well as perfluorinated octanoyl fluonde. Cyclization decreases as initial substrate concentration increases and has been linked to hydrogen-bonded onium polycations [73]. Cyclization is a common phenomenon involving longer (>C4) and branched chains. a-Alkyl-substituted carboxylic acid chlorides, fluorides, and methyl esters produce both the perfluorinated cyclic five- and six-membered ring ethers as well as the perfluorinated acid... 

Electrochemical fluorination of a-cyclohexenyl-substituted carboxylic (acetic, propanoic, butanoic, and pentanoic) acid esters (methyl, ethyl, and propyl) results in a series of both perfluoro-9-alkyl-7-oxabicyclo[4 3 OJnonanes and per-fluoro-8-alkoxy-9-alkyl-7-oxabicyclo[4.3.0]nonanes [<8S] (equation 19)... 

In contrast to phosphorus esters, sulfur esters are usually cleaved at the carbon-oxygen bond with carbon-fluorine bond formation Cleavage of esteri nf methanesulfonic acid, p-toluenesidfonic acid, and especially trifluoromethane-sulfonic acid (tnflic acid) by fluoride ion is the most widely used method for the conversion of hydroxy compounds to fluoro derivatives Potassium fluoride, triethylamine trihydrofluoride, and tetrabutylammonium fluoride are common sources of the fluoride ion For the cleavage of a variety of alkyl mesylates and tosylates with potassium fluoride, polyethylene glycol 400 is a solvent of choice, the yields are limited by solvolysis of the leaving group by the solvent, but this phenomenon is controlled by bulky substituents, either in the sulfonic acid part or in the alcohol part of the ester [42] (equation 29)... 

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