From carbonyl chloride fluoride

Synthesis of carbonyl difluoride from carbonyl chloride fluoride... 

Tri-n-hutylamine Reactions of carbonyl halides with cyclic ethers o>-Chloralkyl fluoroformates from carbonyl chloride fluoride... 

In the carbonyl compounds FC(0)Y the C—F bond distances show a strong dependence on the substituent X and shorten from 136.2(2) pm in acetyl fluoride (Y = Me) to 131.6(1) pm carbonyl fluoride (Y = F). In formyl fluoride (Y = H) and carbonyl chloride fluoride (Y = Cl) the C—F bond lengths are intermediate. When CF2 groups are double-bonded to C, O, S or Se, the C—F bond distances are remarkably constant and range only from 131.5 to 131.9 pm. Such bond lengths, however, are shorter by ca 1.5 pm in compounds with C=N double bonds, such as methanimine or 2,3-diaza-l, 3-butadiene. In both compounds only mean values for the C—F bond distances can be derived from the ED experiments. Ab initio calculations for perfluoromethanimine predict that the C—F bond trans to N—F is longer by 0.4 pm than the cis bond. 

Carbonyl chloride fluoride is conveniently prepared from the reaction of the trichlorofluoromethane, CCI3F, with sulfur(IV) oxide ... 

An alternative means of technical-scale access to fluoroarenes is the fluoroformate method. Starting from the corresponding phenol a fluoroformate is generated by reaction with carbonyl chloride fluoride and subsequently catalytically decarboxy-lated to the aryl fluoride, in the gas phase, by contact with hot platinum [80] (Scheme 2.30). A newer, greener variant of the fluoroformate process has recently been introduced by Rhodia. In this the fluoroformate is formed by the (catalyzed) reaction of the phenol with COj in HF, and the expensive platinum catalyst is replaced by an aluminum-based material. 

Preparation. Wackerle and Ugi have reported an improved procedure in which carbonyl chloride fluoride is generated from trichlorofluoromethane and oleum ... 

Addition of anionic nucleophiles to alkenes and to heteronuclear double bond systems (C=0, C=S) also lies within the scope of this Section. Chloride and cyanide ions are effieient initiators of the polymerization and copolymerization of acrylonitrile in dipolar non-HBD solvents, as reported by Parker [6], Even some 1,3-dipolar cycloaddition reactions leading to heterocyclic compounds are often better carried out in dipolar non-HBD solvents in order to increase rates and yields [311], The rate of alkaline hydrolysis of ethyl and 4-nitrophenyl acetate in dimethyl sulfoxide/water mixtures increases with increasing dimethyl sulfoxide concentration due to the increased activity of the hydroxide ion. This is presumably caused by its reduced solvation in the dipolar non-HBD solvent [312, 313]. Dimethyl sulfoxide greatly accelerates the formation of oximes from carbonyl compounds and hydroxylamine, as shown for substituted 9-oxofluorenes [314]. Nucleophilic attack on carbon disulfide by cyanide ion is possible only in A,A-dimethylformamide [315]. The fluoride ion, dissolved as tetraalkylammo-nium fluoride in dipolar difluoromethane, even reacts with carbon dioxide to yield the fluorocarbonate ion, F-C02 [840]. 

Chloroformates, carbonyl chlorides and acid chlorides are converted into the corresponding fluorides 1 in excellent yield upon treatment with potassium fluoride in the presence of 18-crown-6 at room temperature. Fluoroformates are also synthesized from chloroformates by fluorination with potassium fluoride in acetylacetone at 60"C under UV irradiation, with potassium fluoride in nitrobenzene,- with potassium fluoride in the absence of a solvent at temperatures in the range 100-250 and with thallium(I) fluoride. 

A considerable amount of research has been concerned with the nature of the electrophiles that are involved in Friedel-Crafts acylation reactions. We will summarize the main points. Acyl halides and carboxylic acid anhydrides have been known, for many years, to form stable complexes with a variety of acid catalysts. A well-defined product is formed between acetyl fluoride and boron trifluoride at low temperatures. Analytical and conductivity data characterized the material as acetylium tetrafluoroborate, and this was further confirmed by IR measurements. In the system acetyl chloride-aluminum chloride the acetylium ion can be differentiated from the donor-acceptor complex involving the carbonyl group by means of their IR carbonyl stetching frequencies. A number of other acyl fluorides have been shown to form well-defined acylium salts by interaction with a number of metal fluorides. Acylium salts can also be prepared from acyl chlorides by means of metathetical reactions involving anhydrous salts such as silver hexafluoroantimonate. As well as characterization by means of IR spectroscopy, acylium salts have been studied in non-nucleophilic solvents by NMR spectroscopy. The NMR data for the ben-... 

Sulfur tetrafluoride [7783-60-0] SF, replaces halogen in haloalkanes, haloalkenes, and aryl chlorides, but is only effective (even at elevated temperatures) in the presence of a Lewis acid catalyst. The reagent is most often used in the replacement of carbonyl oxygen with fluorine (15,16). Aldehydes and ketones react readily, particularly if no alpha-hydrogen atoms are present (eg, benzal fluoride [455-31-2] from benzaldehyde), but acids, esters, acid chlorides, and anhydrides are very sluggish. However, these reactions can be catalyzed by Lewis acids (HP, BF, etc). 

Ab initio molecular orbital calculations are being used to study the reactions of anionic nucleophiles with carbonyl compounds in the gas phase. A rich variety of energy surfaces is found as shown here for reactions of hydroxide ion with methyl formate and formaldehyde, chloride ion with formyl and acetyl chloride, and fluoride ion with formyl fluoride. Extension of these investigations to determine the influence of solvation on the energy profiles is also underway the statistical mechanics approach is outlined and illustrated by results from Monte Carlo simulations for the addition of hydroxide ion to formaldehyde in water. 

When sodium ethoxide is used in place of sodium hydroxide in the carbonylation reaction of benzyl halides with dicobalt octacarbonyl, ethyl esters are produced instead of the acids [15], Esters are also produced directly from iodoalkanes through their reaction with molybdenum hexacarbonyl in the presence of tetra-/i-butylammo-nium fluoride [16]. Di-iodoalkanes produce lactones [16]. The reaction can be made catalytic in the hexacarbonyl by the addition of methyl formate [16]. t-Butyl arylacetic esters are produced in moderate yield (40-60%) under phase-transfer catalytic conditions in the palladium promoted carbonylation reaction with benzyl chlorides [17]. 

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