Silver hexafluoroantimonate

The silver fluorocomplexes, ie, silver hexafluoroantimonate [26042-64-8], AgSbF silver hexafluorophosphate [26042-63-7], AgPF silver tetrafluoroborate [14104-20-2], AgBF and other salts such as silver trifluoromethane sulfonate [2923-28-6], CF SO Ag, and silver trifluoroacetate [2966-50-9], CF COOAg, play an important role in the synthesis of organic compounds and have gained potential industrial importance. 

These compounds perform a dual function in synthesis procedures. The introduction of a complex anion assists in the stabilization of the desired product and the generation of unique intermediates by chloride displacement, eg, silver hexafluorophosphate, AgPF, forms adducts with neutral diamagnetic organometaHics which can act as controUed sources of highly reactive cations (29). Silver hexafluoroantimonate, AgSbF, is an electrophilic... 

In 2000 Xumu Zhang and co-workers reported a bisphosphine complex of rhodium, [RhCl(dppb)]2, which, when used with silver hexafluoroantimonate, in some cases offers a rate advantage over the Wilkinson s catalyst/silver triflate system [28], allowing the reaction to be conducted at room temperature (Tab. 13.5). Scott Gilbertson and coworkers reported a related example, employing [Rh(dppe)(CH2Cl2)2] SbFg as a catalyst for the [5+2] reaction (Tab. 13.5, entry 5) [29]. 

In the presence of a catalytic amount of an antunony(V) salt (SbCU SbFe ), generated from antimony(V) chloride and silver hexafluoroantimonate, the Beckmann rearrangement of several ketoxime trimethylsilyl ethers proceeds smoothly to give the corresponding amides or lactams in good yields . ... 

Silver hexafluoroantimonate (3.4 mg) was placed in another flask under nitrogen and to this flask was added the above palladium complex solution. After being stirred for 1 h at room temperature, the mixture was Altered through a short pad of Celite under nitrogen. 

The reactions of chlorosilicon and chlorogermanium transition metal complexes with silver hexafluoroantimonate, as well as with silver tetrafluoroborate or silver hexafluorophosphate. 

The reactive cyclopropylidene cyclopropylcarbinyl cation 37 was generated from the corresponding bromide and silver hexafluoroantimonate, and was reacted in situ with olefins such as cyclohexene to form the addition products (equation 33). On the other hand, under the same conditions, the isopropylidene cyclopropylcarbinyl cation 41 rearranged spontaneously by ring expansion (equation 34)71. 

Silver(I) acetate, 396 Silver hexafluoroantimonate, 467 Silver imidazolate, 467 Silver nitrite-Mercury(II) chloride, 467-468 Silver(l) oxide, 468-469 Silver(II) oxide, 469 Silver perchlorate, 469-470 Silver tetrafluoroborate, 471 Silver(I) trifluoracetate, 471 Simmons-Smith reagent, 210-211, 472, 598 Sinularene, 246 Slaframine, 114, 115 Sodium amalgam, 473-475 Sodium-Ammonia, 472 Sodium benzeneselenoate, 475 Sodium bicarbonate, 476 Sodium bis(methoxyethoxy)aluminum hydride, 93, 476-477 Sodium borate, 322 Sodium borohydride, 477-479, 499 Sodium borohydride-Cobalt(IF) chloride, 479 Sodium borohydride-Methanesulfonic acid,... 

Ley et al. also applied this method to the synthesis of sesquiterpenes through a strategy involving a Diels-Alder reaction. Taking into account the effect of conditions and silver counterion on allene isomerization (see Scheme 33), they obtained the diene partner via isomerization of the acetoxyallene produced on treatment of a propargyl acetate with catalytic amount of silver hexafluoroantimonate (Scheme 3.36).57... 

The silver-catalyzed, propargyl Claisen rearrangement has also been combined with cyclization reactions. Propargyl ethers derived from [3-ketoesters were rearranged by silver hexafluoroantimonate and the resulting allenic [3-ketoesters cyclized on treatment with base, leading to the formation of 2/7-pyrans in moderate to excellent yields (Scheme 3.48).75 The cyclization process was described as a base-catalyzed... 

As already mentioned, oxocarbenium salts are efficient initiators42,45 for the polymerization of oxolane. They can be prepared in situ by a metathetic reaction between the corresponding acyl halide and silver hexafluoroantimonate ... 

Two block copolymers of trimethylcellulose-b-polyoxyethylene have been reported (139). The trimethylcellulose blocks containing one a-chloro ether end were treated with silver hexafluoroantimonate, AgSbF, in THF solution between — 10 C and + 23 C to facilitate a living cationic THF polymerization of polyoxytetramethylene blocks, as shown in Fig. 8. 

TABLE 2. Selected Step 1 norbornene pentafluoroketal derivatives that were converted into the corresponding polyhornene derivative using di-p-chlorohis[(i]-allyl) palladium(II)]and silver hexafluoroantimonate. 

Photodilorination has been recommended for the preparation of choice of cyclodecene finom cyclodecane via the intermediate chloride. Bromine is a rather weak brominating agent for alkanes a only unusually favorable substrates, like adamantane, react at a reasonable rate. The mixture HgO/Brz is much more reactive than bromine itself, as shown by the facile tHomination of 1,1,3,3-tetramethylbutane. Silver hexafluoroantimonate has dso been used to activate bromine for this type of reaction. Iodine is normally ineffective in functionalizing alkanes, but use of y-itradiation of a solution of I2 in alkanes leads to unselective formation of all possible iodoalkanes. ... 

Electrophilic bromination of alkanes in solution was also carried out with Br2 in the presence of silver hexafluoroantimonate. Scheme 6.23, again. 

The cationic palladium catalysts are typically prepared by reacting (cyclooctadi-enejpaUadium methyl chloride with a stoichiometric amount of the bidentate ligand to afford the (ligand) Pd(Me)Cl adduct The adduct is then reacted with an activator such as silver hexafluoroantimonate, to afford the final cationic catalyst, (hgand) l l(Me) SbF[]. The polymerization reactions were typically run at ambient temperature in toluene to afford a viscous solution of the desired copolymer. Other activators used include tris(pentafluorophenyl)borane/triethylaluminum mixtures, Nal (C,H 5(fT j)2)4 and mefhaluminoxane. 

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-... 

Gold(I) chloride - tertiary phosphine/silver hexafluoroantimonate-acetonitrile complex... 

Table 3.2 Acylation of aromatics with anhydrides catalyzed by dichlorobis(benzonitrile)platinum(Il)-silver hexafluoroantimonate mixture...

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