Preparation perfluoroalkyl 7?6-

The reaction of perfluoroalkyl iodides with alkenes affords the perfluoro-alkylated alkyl iodides 931. Q.a-Difluoro-functionalized phosphonates are prepared by the addition of the iododifluoromethylphosphonate (932) at room temperature[778], A one-electron transfer-initiated radical mechanism has been proposed for the addition reaction. Addition to alkynes affords 1-perfluoro-alkyl-2-iodoalkenes (933)[779-781]. The fluorine-containing oxirane 934 is obtained by the reaction of allyl aicohol[782]. Under a CO atmosphere, the carbocarbonylation of the alkenol 935 and the alkynol 937 takes place with perfluoroalkyl iodides to give the fluorine-containing lactones 936 and 938[783]. 

The higher molecular weight petfluoroalkyl iodides ate prepared by telomerization of tetrafluoroethylene with lower molecular weight perfluoroalkyl iodides (46,48). 

Many of the perfluoroaLkyl carboxyUc acids were first prepared by the electrochemical fluorination (ECF) of the corresponding carboxyUc acids (7). In ECF acid chlorides are converted to the corresponding perfluoroacid fluorides as shown in equation 1 for octanoyl chloride. 

Alkyl-5-arylisoxazoles (303) were prepared by the regiospecific reaction of appropriate 1,3-diketones (302) (R = alkyl or perfluoroalkyl) with hydroxylamine hydrochloride in pyridine (79MI41601). 

Polymer-bound phenyliodine difluoride, which also has been used as a reagent to add fluorine to alkenes, can be prepared by the addition of xenon difluoride to the polymer [134, 135 136] Methyl iodide is converted to trifluoro methyliodine difluoride by treatment with fluorine at -110 C [137] Perfluoro-alkyliodine tetrafluorides could be synthesized from the perfluoroalkyliodine difluorides and fluorine [138] or chlorine trifluoride [139] Perfluoroalkyl [140] and perfluoroaryl [141] iodides are oxidized to the corresponding iodine difluorides by chlorine trifluoride. 

Acid hydrolysis of (i-perfluoroalkylvinylamines, prepared from secondary amines and perfluoroalkylacetylenes, yields p-aminovinyl perfluoroalkyl ketones as the major products [79] (equation 20)... 

Another way to prepare fluorinated sulfides is the photochemical alkylation of sulfides or disulfides by perfluoroalkyl iodides [69, 70, 71] (equations 62-64). Reaction of trifluoromethyl bromide with alkyl or aryl disulfides in the presence of a sulfur dioxide radical anion precursor, such as sodium hydroxymethanesulfi-nate, affords trifluoromethyl sulfides [72] (equation 65). 

Hydrocarbon Gngnard reagents give the alkyl cyanides, whereas perfluo-rinated Grignard reagents produce the sulfides This reaction is useful for the preparation of alkyl perfluoroalkyl sulfides to the exclusion of di and polysulfides, which are produced by other methods... 

The reaction of perfluoroalkyl iodides with calcium amalgam at -20 to 40 °C has been used to prepare perfluoroalkyl carbinols in 30-70% yields [/, 2] Aromatic aldehydes (equation 1) and ketones (equation 2) undergo this reaction, aliphatic aldehydes give high boiling mixtures The results are interpreted in terms of the intermediate formation of an organocalcium species... 

Trmlkylperfluomalkylnn derivatives can be prepared via metathesis of tnmethylbn trifluoroacetate with bis(perfluoroalkyl)eadmium reagents [4 (equation 3)... 

The importance of solvent effects in the preparation of perfluoroalkyzinc reagents is further illustrated in the reaction of perfluoroalkyl iodides with zinc-copper couple. In DMSO, DMF, and HMPA, the main products are the fluo-roolefins The formation of the fluoroolefin is facilitated when the reaction is carried out in the presence of potassium thiocyanate [30] (equation 21)... 

Tnfluoromethanesulfinate can be prepared from the reaction of trifluoromethyl bromide with sulfur dioxide and zinc [50] (equation 41) Similar insertion occurs when perfluoroalkyl iodides are used as precursors (equations 41 and 42)... 

An alternative method, which avoids the prior preparation of the toxic di-alkylcadmiums, is direct reaction of the perfluoroalkyl iodide with cadmium metal [729] (equation 98)... 

Typical perfluoroalkylated aromatic derivatives prepared via this type of reaction are illustrated in Table 6. This methodology has been used for the preparation 5-(perfluoroalkyl)pyrimidines [194], heptafluoroisopropylated aromatics... 

Table 6, Perfluoroalkyl Aromatic Compounds Prepared via the Reaction of Perfluoroalkylcopper Reagents with lodo-or Bromoaromatic Compounds...

Perfluoroalkyl- and perfluoroaryltitanium compounds were prepared m situ via reaction of the corresponding Gngnard reagents with chlorotris(diethyl-amido)titanium [28S] Reaction of the titanium compounds with aldehydes resulted in fluoroalkylative amination [288] (equation 192)... 

The scope of haloaliphatic additions to alkenes has been extended to the preparation of 1,2-bis(perfluoroalkyl)iodoethanes by the addition of perfluoroalkyl iodides tofluoroalkyl alkenes [73] (equation 12) or to alkadienes [14] (equation 13)... 

Perfluoroalkyl groups adjacent to multiple bond systems lower the frontier molecular orbitals (FMOs) Therefore, cycloaddition reactions preferentially occur with electron-rich multiple-bond systems The preference of bis(trifluoromethyl)-substituted hetero-l,3-dienes for polar reacuons makes them excellent model compounds for developing new types of diene reactions deviating from the well documented Diels-Alder scheme (pathway 1) A systematic study of the reactions of diene (1 =2-3=4)-dienophile (5=6) combinations reveals new synthetic possibilities that have not yet been fully exploited as tools for preparative organic cherrustry (equation 25)... 

An interesting development of this research is the preparation of polymer-supported FITS reagent from bis(trifluoroacetoxy)iodoperfluoroalkanes and Nafion-H [145]. FITS-Nafion reacts with organic substrates that react to usual FITS reagents, but the products of the perfluoroalkylation reaction can be separated easily from the insoluble resin by filtration [145]... 

Selenium analogues RN=SeCl2 are unknown for R = aryl or alkyl and thermally unstable when R = CE3 or C2E5. The perfluoroalkyl derivatives are prepared by the reaction of dichloroamino compounds and Sc2Cl2 in CCI3E (Eq. 8.18), but they decompose at room temperature to the corresponding diazene and a mixture of selenium chlorides. 

Chlorotrifluoroethylene was converted in one step using nBuLi to dieth-ylfluoromalonate, which was a useful precursor for 5-fluorouracil (84CL1573). Fluorinated pyrimidinones can also be obtained from a,fi-unsaturated carboxylic acid derivatives prepared from 1-phosphonyloxy-perfluoroalkyl-l-alkenephosphonates (86TL2879). 

Perfluoroalkyl group-containing surfactants like fluoroalkylsuccinamic surfactant and fluoroalkylthio derivatives from the reaction of bis-2-hydroxyethyl-aminomethylphosphonic acid ester with maleic anhydride were especially useful for the preparation of foams for extinguishing burning hydrocarbon liquids. A surface tension of 19.8 mN/m in a 0.1% aqueous solution was observed [88. ... 

Perfluoroalkyl)-5 -deoxy-5 -fluoro- and 5-(perfluoroalkyl)-2, 5 -di-deoxy-5 -fluoro-uridines were prepared " from 840 and 834, respectively, using perfluoroalkyl-copper complexes. Among them, 5 -deoxy-5 -fluoro-(846) and 2, 5 -dideoxy-5 -fluoro-5-(perfluoroethyl)uridine (839) were particularly effective against Ehrlich ascites carcinoma. 5-Hydroxyl (847) and 5-amino or 5-alkylamino (5-NHMe, -NHBu, -NHCH2Ph, -morpholino, -piperidino, and -pyrrolo) analogs (848) of 840 were prepared. The a anomer of 5 -deoxy-5 -fluorouridine (840) was also synthesized. "... 

This study relates to a continuous process for the preparation of perfluoroalkyl iodides over nanosized metal catalysts in gas phase. The water-alcohol method provided more dispersed catalysts than the impregnation method. The Cu particles of about 20 nm showed enhanced stability and higher activity than the particles larger than 40 nm. This was correlated with the distribution of copper particle sizes shown by XRD and TEM. Compared with silver and zinc, copper is better active and stable metal. 

Industrially, the perfluoroalkyl iodides by telomerization are mostly made by a batch system using peroxide initiators. However, the difficulty of mass production, and the production of hydrogen-containing byproducts in the process are disadvantageous [4]. In this study, a continuous process for the preparation of perfluoroalkyl iodides over nanosized metal catalysts in gas phase and the effects of the particle size on the catalytic activities of different the preparation methods and active metals were considered. 

A -azaphosphorins (233), respectively. The perfluoroalkyl-substituted A5-phosphatriazines (234) have been prepared from the... 

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