Trifluoromethanesulfonate, salts

Complexes of Me [14]-4,1 l-dieneN4 are, however, more conveniently prepared by reaction of the dianiono salt of the free organic ligand with metal carbonates or acetates in methanol or water-methanol mixtures. The isolation of the free organic ligand salt is achieved by the reaction of the monoperchlorate, or similar salt of ethylenediamine, with acetone or mesityl oxide (4-methyl-3-penten-2-one). The material can also be isolated from the reaction mixture produced by tris(ethylenediamine)iron(lI) perchlorate and acetone. The preparations described here involve the reaction of the ciperchlorate or bis(trifluoromethanesulfonate) salt of Me [14]-4,1 l-dieneN4 with the appropriate metal ion. 

Cyclopropenones were protonated at the carbonyl oxygen to give the hydroxycyclo-propenylium ions in solution, e.g. the dimethylamino-substituted derivative 3 was protonated and isolated as the crystalline trifluoromethanesulfonate salt. "... 

Disubstituted cyclopropenones 1 were converted into the highly moisture-sensitive trifluoromethanesulfonate salts of the bis(cyclopropenyliumyl) ether dications by the reaction with 0.5 equivalents of triflic anhydride. " ... 

The reactivity of the trichlorocyclopropenylium ion exhibited a marked dependence on its counterion. In contrast to the tetrachloroaluminate salt, the trifluoromethanesulfonate salt 7 reacted with a large excess of benzene or fluorobenzene to give the corresponding triarylcyclo-propenylium salts 8 in good yield. By using the hexachloroantimonate salt 9, the trichlorocyclopropenylium ion underwent trisubstitution by disubstituted alkenes via the addition-elimination mechanism this reaction was not attained with the use of other counterions. ... 

In an important achievement Vo-Thanh and co-workers realized that chiral ionic liquids such as 35 can act as chiral inducers for the asymmetric MBH reaction.The V-octyl-V-methylephedrinium trifluoromethanesulfonate salt 35, used as solvent in the DABCO-mediated reaction of methyl acrylate and benzaldehyde, produced the corresponding allylic alcohol in 60% yield and 44% ee after 7 days at 30 °C. 

A gentle method for the formation of trifluoromethanesulfonate salts of some condensed triazine systems, e.g. 6, involves treatment of the free bases 5 with trimethylsilyl trifluoromethanesulfonate followed by methanol or ethyl acetate containing water,31... 

Reaction of bis(triphenyl) oxodiphosphonium trifluoromethanesulfonate salt with 3-tosylamino-a-acylamino esters 78 led to a highly efficient enantiospecific synthesis of imidazolines 79 <04OL1681>. AT-Acylated a-aminonitriles 80 were reacted with triphenylphosphine and carbon tetrachloride to afford 2,4-disubstituted 5-chloro-l//-imidazoles 81, which could undergo Suzuki palladium-catalyzed reactions <04OL929>. 

A useful feature of this reagent is that high ratios of ortho to para products are found for some substituted aromatics. Finally, it possible to use nitronium-ion salts for nitration. Nitronium fluoroborate has been extensively studied. The trifluoromethanesulfonate salt is also readily prepared and is an active nitrating... 

Pivaloyl chloride (24.2 g, 0.2 mol) and tert-hwiy alcohol (3.7 g, 0.05 mol) were combined and the mixture was heated to 85 °C. Triflic acid (15 g, 0.1 mol) was added over a period of 15 min. After the triflic acid addition was completed the mixture was stirred for an additional 10 min at 85 °C. The light brown reaction mixture was then cooled in an ice bath and poured into 100 mL of cold ethyl ether. The light tan precipitate was collected by filtration and air dried to give 9.6 g (54%) of pyrylium salt that was used without further purification in the next step. [Note The pyrylium trifluoromethanesulfonate salt does not have the explosive hazard of the corresponding perchlorate]... 

The Stevens rearrangement of azetidinium trifluoromethanesulfonate salts 96-98 possessing a methyl and benzyl group on the nitrogen in the... 

The interaction of tris(2-aminoethyl)amine (L685) with bis(dimethylamino)-methane in the presence of trifluoromethanesulfonate salts of lanthanides(III),... 

Transition metal cations solvated by weakly coordinating solvents are useful precursors for a variety of nonaqueous synthetic applications. The dissociation of acetonitrile ligands opens up vacant coordination sites for catalysis, and allows transition metals to be introduced into extended arrays formed by condensation reactions with polydentate ligandsAlthough salts of homoleptic acetonitrile metal cations with tetrafluoroborate anions have been known since the 1960s, there has been no detailed description of the syntheses and characterization of these compounds. Likewise, there have been general descriptions of the syntheses of trifluoromethanesulfonate salts, but no specific outline for individual metals has been published. In this report, the syntheses of [M (CH3CN)x][BF4]2 (M = Cr,Mn,Fe,Co,Ni,Cu) and [M CHaCNlJlSOsCFsla (M = Mn,Fe,Co,Ni) are described. Two different methods are used to prepare tetrafluoroborate salts (1) the oxidation of metals with nitrosonium tetrafluoroborate, first described by Hathaway et al. and (2) the dehydration of aqueous tetrafluoroborate salts in a Soxhlet extractor with molecular sieves. The oxidation reaction is rapid, anhydrous, and recommended for smaller-scale preparations because of the relatively... 

Scheme 4.11 Ring expansion of 2-alkenylazetidinium trifluoromethanesulfonate salts to...

In certain cases, homoleptic solvento-complexes containing halides as counterions have been prepared (see Table 4.2). In general, preparation of such homoleptic solvento-complexes is of limited use due to the difficulties inherent in the preparation of the necessary anhydrous salts. In recent years it has been found that trifluoromethanesulfonate salts are easily prepared in anhydrous form. The CF3S03 ion only rarely fomas isolable complexes in which it is coordinated to a metal ion and is normally a weaker donor than the perchlorate anion. Unlike the common perchlorate salts, metal trifluoromethanesulfonates are not typically explosive under normal laboratory conditions. Thus, anhydrous met trifluoromethanesulfonates are very useful precursors in the preparation of homoleptic solvento-complexes. 

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