Tetraalkylammonium cyanides

The reactions of white phosphorus with tetraalkylammonium cyanides in the presence of a crown ether in acetonitrile give rise to the dicyanophosphide ion, which is found to react with a variety of anionic phosphorus nucleophiles with displacement of cyanide ion to generate new P-P bonded compounds.7... 

A recently developed general method of synthesis for the tetraalkylammonium cyanides was extended subsequently to the cyanates. Previous to... 

In 2010, Bernal, Fernandez, and Lassaletta [198] disclosed an unprecedented asymmetric cyanosilylation of nitroalkenes that was catalyzed enantioselectively by a quinine derivative with tetraalkylammonium cyanide and thiourea moieties. The activation of the nitroalkene takes place by hydrogen bonding to the thiourea, while the tetraalkylammonium cation moiety binds the cyanide anion, which is dehvered stereoselectively to the double bond. 

Trifluoromethanesulfonic acid in the presence of anisole cleaves a number of protecting groups currently used in peptide chemistry without significant side reactions Tetraalkylammonium cyanides, which are soluble in organic solvents, catalyze Michael additions and other base-catalyzed reactions. As nucleophiles they are more powerful than NaCN . 

In 1971, Starks introduced the term phase-transfer catalysis to explain the critical role of tetraalkylammonium or phosphonium salts (Q 1 X ) in the reactions between two substances located in different immiscible phases [1], For instance, the displacement reaction of 1-chlorooctane with aqueous sodium cyanide is accelerated many thousand-fold by the addition of hexadecyltributylphosphonium bromide 1 as a phase-transfer catalyst (Scheme 1.1). The key element of this tremendous reactivity enhancement is the generation of quaternary phosphonium cyanide, which renders the cyanide anion organic soluble and sufficiently nucleophilic. 

Strecker-type reaction of TMS cyanide with chiral sulfinimines gives diastereoselective cyanations at the imine carbon, at —78 °C in DMF, using simple metal-free Lewis base catalysts such as tetraalkylammonium carboxylates.73... 

The tetraphenylarsonium cation is useful in coordination chemistry because of its large size. Tetraphenylarsonium cyanate dihydrate was prepared byNor-buryand Sinhain 1968. The preparation involved precipitation of the cyanate from an aqueous solution, but the method suffers from the disadvantage of low yields. Tetraphenylarsonium cyanide has been prepared from methanol solution with fairly good yields, but the product is isolated as the monohydrate. The ion-exchange method developed for the tetraalkylammonium salts can be readily applied to the preparation of anhydrous tetraphenylarsonium cyanate and cyanide, thus eliminating many of the problems initially involved in the synthesis of these componds. 

Many salts are soluble in DMSO, so the choice of supporting electrolyte is less restricted than in most other nonaqueous solvents. In general, perchlorates, even KCIO4, nitrates, and halides, are soluble, whereas fluorides, cyanides, sulfates, and carbonates are not thus not only NaC104, LiCl, NaNO, and tetraalkylammonium salts can be used but also such salts as NH4PF6 and NH4SCN. The ability of DMSO to solvate ions is also of importance in the indirect electrolytic hydrodimerization of, for example, acrylonitrile using Na(Hg) [388]. 

Of particular practical interest are methods based on the conversion of halides into the corresponding tetraalkylammonium salts, thermal decomposition of these salts to give alkyl halides, and GC analysis of the latter [144,145]. Reaction chromatographic methods of determining other anions, such as phosphates [146—148], silicates [149— 151], cyanides and thiocyanides [153] have also been described. 

Tetrabutylammonium cyanide Reactions with tetraalkylammonium salts Benzoins from aldehydes... 

Organic-inorganic contact can be improved by the use of tetraalkylammonium in place of alkali metal ions. - E A mixture of benzaldehyde, tetrabutylammonium cyanide, and water stirred ca. 1 hr. at room temp. benzoin. Y 70%. J. Solodar, Tetrah. Let. 1971, 287. 

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