Nitrosyl hexafluorophosphate

Protonic initiation is also the end result of a large number of other initiating systems. Strong acids are generated in situ by a variety of different chemistries (6). These include initiation by carbenium ions, eg, trityl or diazonium salts (151) by an electric current in the presence of a quartenary ammonium salt (152) by halonium, triaryl sulfonium, and triaryl selenonium salts with uv irradiation (153—155) by mercuric perchlorate, nitrosyl hexafluorophosphate, or nitryl hexafluorophosphate (156) and by interaction of free radicals with certain metal salts (157). Reports of "new" initiating systems are often the result of such secondary reactions. Other reports suggest standard polymerization processes with perhaps novel anions. These latter include (Tf)4Al (158) heteropoly acids, eg, tungstophosphate anion (159,160) transition-metal-based systems, eg, Pt (161) or rare earths (162) and numerous systems based on tri flic acid (158,163—166). Coordination polymerization of THF may be in a different class (167). 

Neutral (cyclohexadienyl)manganese complexes 71, generated by nucleophilic addition to (arene)Mn(CO)3+ cations 65, undergo ligand substitution with nitrosyl hexafluorophosphate to give the corresponding (cyclohexadienyl)Mn(CO)2NO+ cations 72 (Scheme 17)93. Attack by a wide variety of nucleophiles on cations 72... 

Cram (98) using nitrosyl hexafluorophosphate or nitrous acid. Oae and his group (99) also have reported a method for the stereospecific deimination of 60 by means of elemental sulfur or diphenyl disulfide at 160°C. All these procedures give chiral sulfoxide with the same configuration at sulfur as that of the starting sulfoximides 60. 

Reaction of the 1,3,2-benzodiselenastannole (166) with selenium tetrachloride gives the triselenole (40) which is converted into the triselenolium hexafluorophosphate (20b) by reaction with nitrosyl hexafluorophosphate <94CC1593>. Benzo[l,2-rf][l,2,3]triselenolium chloride (20c) was obtained by reaction of 1,2-benzene-bis(selenenyl chloride) with selenium <92AG(E)779>. The structure of the trifluoromethanesulfonate (20a) has been established by x-ray crystallography (see Section 4.21.3.1). 

Although fluorine is known to be a rather poor leaving group in substitution reactions, some examples have been reported for the replacement of fluorine by N-nucleophiles. Here, substitution can proceed with amines,1 -3 amides,4 amidines,5-6 hydrazines3-7 or azides.8-9 Nitriles in the presence of nitrosyl hexafluorophosphate replace fluorine in alkyl fluorides, in a Ritter-like reaction, to form tV-alkylnitrilium species, which are hydrolyzed to amides.10... 

There are only two reports of electrophilic attack on aromatic oxathioles. The cyclization of (62) in TFA generates the 1,3-oxathiolium (63), which cannot be isolated as such but which suffers acylation to give the stable derivative (64). It is unclear whether the nitrosation of thiapentalene (65) represents an electrophilic attack on the intact system or whether attack occurs on the ring-opened species (66). In the event, nitrosyl hexafluorophosphate... 

A detailed account of nitrosation reactions is available (74JCS(Pi)722). Generally, nitrosation which occurs at position 3 or 4 is accompanied by a rearrangement of the triatomic sequence 1,6,6a, with formation of a l-oxa-6,6aA4-dithia-2-azapentalene, as indicated in Scheme 2. l,6-Dioxa-6aA4-thiapentalene reacts similarly with nitrosyl hexafluorophosphate. 

PMQ3 was doped with nitrosyl hexafluorophosphate (NFP) (0.TOPFg/monomer) and iodine (1.14 1/ monomer). 

Nitrosonium hexafluorophosphate (Nitrosyl hexafluorophosphate). NO PFe. Mol. wl. 174,99. Supplier Ozark Mahoning Corp. 

The reaction is conducted in an atmosphere of dry nitrogen, and the acetonitrile must be dried before use (molecular sieves are satisfactory), since nitrosyl hexafluorophosphate is easily hydrolyzed. To 2 g. of tricarbonyl- -cyclopentadienylmanganese1 in 100 ml. of acetonitrile is added dropwise, and with rapid stirring, a solution of 1.9 g. [NO] [PF6] in 30 ml. of acetonitrile. Carbon monoxide is evolved, and the solution becomes darker yellow. After the addition of the [NO][PF6] solution is complete (5 minutes), stirring is continued for 10 minutes to ensure complete reaction. The volume of the solvent is reduced to approximately 20 ml. by evaporation,... 

Diselenide dication (51) is formed via a two-electron oxidation of 1,5-diselenacyclooctane (52) with two equivalents of a one-electron oxidizing agent, nitrosyl hexafluorophosphate or nitrosyl tetrafluoroborate as shown in Equation (16). Six- and ten-membered ring bis-selenides (56) and (54) are oxidized similarly to the dications (55) and (53) respectively <93T1605>. The ease with which l,4-diselenoniabicyclo[2.2.0] salt (55) is obtained from 1,4-diselenacyclohexane (56) is somewhat surprising since the transannular interaction between the two selenium atoms at 1,4-positions is not expected to be extensive. 

The Te-dication (58) is prepared from 1,5-ditellurocyclooctane (59) using a similar synthetic strategy to those utilized for the syntheses of S- and Se-dications. Two equivalents of nitrosyl hexafluorophosphate or tetrafluoroborate gives the PF or Bp4 salt of the Te-dication (58) as shown in Equation (18). The cyclic bis-telluride (59) is prepared using standard methods (Scheme 16). The Te-dication (58) can also be prepared by the ddq oxidation of the cyclic bis-telluride (59). 

Treatment of peracyl 6-azido-6-deoxy-hexopyranosides with nitrosyl hexafluorophosphate in acetonitrile leads to dloxolanlum Ions which may rearrange when there Is a vicinal, axially oriented ester group, as shown in Scheme 1. Where this condition is not met, no rearrange-ment occurs, thus explaining the results reported in Vol. 15 p.69-70. ... 

A soln. of nitrosyl hexafluorophosphate in acetonitrile added dropwise, with stirring, during 20 min to a soln. of startg. ethylene deriv. in the same solvent at —23° under N2, stirring continued for 30 min, and left at room temp, until the mixture turned dark purple - product. Y 65%. F.e. inch 4,4,6,6-tetraaryl-derivs. s. G.H. Lee et al., Tetrahedron Letters 29, 4437-40 (1988). 

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