Reaction with cyanide ions

The HOI would be rapidly reduced by iodide and the Mn(V) species would be expected either to disproportionate or to oxidise further iodide. This reaction scheme has features in common with the analogous reaction with cyanide ion discussed below. 

Reissert compounds (>70%), derived from benzimidazole, phthalazine, quinoline and isoquinoline, have been prepared by a simple catalysed one-pot N-acylation of the appropriate heterocycle, followed by reaction with cyanide ion [e.g. 101-103],... 

Consequently, the triplet lifetime of 2-nitrothiophene in water is ca. 5 10 s and ca. 10 s in 0-01 M KCN. Owing to the extremely fast reaction with cyanide ion, the triplet lifetime, which in water is reasonably long, appears to be considerably reduced in the presence of even moderate cyanide concentrations. 

This is a synthetically useful procedure because the a-halo acids are useful starting materials for other reactions. For example, the addition of hydroxide ion leads to the replacement of the halogen with an -OH group. The reaction with ammonia replaces the halogen with -NH2. The reaction with cyanide ion, CN , converts the halide to a nitrile. Figure 12-33 illustrates this reaction. 

Elemental composition Ni 53.00%, C 21.69%, N 25.30%. The compound may be identified by x-ray and selective chemical reactions with cyanide ions. Nickel may be analyzed in an acidified aqueous solution after it is solubilized with concentrated nitric acid or aqua regia (See Nickel). 

Elemental composition Ag 75.26%, Cl 24.74%. The salt is dissolved in concentrated sulfuric acid, diluted, and analyzed for silver (see Silver). Solid powder may be characterized by its physical properties and its reaction with cyanide ion, forming the complex ion [Ag(CN)2]. ... 

Notably, as illustrated in Scheme 124, enantiofaces of aldehydes can be differentiated by a chiral rhenium template to result in stereoselective reaction with cyanide ion (297). The rhenium Lewis acid element forms stereoisomeric it complexes with aldehydes, which are convertible via... 

The nickel-catalyzed transformation of aromatic halides into the corresponding nitriles by reaction with cyanide ions is reported. Both tris(triarylphosphine)nickel(0) complexes and tY2ins-chloro( aryl )bis( triarylphosphine )nickel(II) complexes catalyze the reaction. The influence of solvents, organophos-phines, and substituents on the aromatic nucleus on catalytic cyanation is studied. A mechanism of the catalytic process is suggested based on the study of stoichiometric cyanation of ti3ins-chloro(aryl)bis(triphenylphosphine)nickel-(II) complexes with NaCN and the oxidative addition reaction of Ni[P(C6H5)3]s with substituted aryl halides. 

Since methionine seems to be bound in both oxidation states, and yet is the more labile axial ligand in the reaction with cyanide ion, the NMR data seem to support that histidine is also an axial ligand in ferri- and ferrocytochrome c. Direct identification of the axial histidine in the... 

Preparation by way of the nitrile will not be feasible. Rather than react with sodium cyanide by substitution, ferf-butyl chloride will undergo elimination exclusively. The SN2 reaction with cyanide ion is limited to primary and secondary alkyl halides. 

Reaction with Cyanide Ion. Potassium cyanide in methanol also reacts rapidly with l to give a monocyano adduct, 2 (eq. 19). 

Protonation with HCIO4 of 2-(/ -tolyl)-2,3-didehydrosparteine 76 resulted in the formation of an immonium bond gave 77 which, upon reaction with cyanide ion, led to the introduction of the cyano group in position 2 of the sparteine system affording 78 (Scheme 12) <2004JST(688)111>. 

Both compounds show poorly resolved spectra in the visible-UV region, with intense bands presumably of charge-transfer origin. Reaction with cyanide ion ultimately results in formation of the Pt(CN)4"ion in solution. 

Further reaction of the sulfenyl chlorides to the sulfides does not take place. It can also be deduced that the substitution reaction occurred with the chelate ring unruptured, since no sulfides (usually obtained with sulfur dichloride and the enol form of 2,4-pentanedione) were obtained. The structures of the sulfenyl chlorides of the metal acetylacetonates were confirmed by their infrared spectra, and by conversion of the sulfenyl chloride to a thiocyano group by reaction with cyanide ions. The tris(3-thiocyano-... 

Reissert type reactions of pyridazine 1-A -oxides to give 6-cyanopyridazines in poor yield, and the alkylation of a phthalazine Reissert compound to give 1 -methylphthalazine after hydrolysis, were discussed in CHEC-I <84CHEC-1(3B)1). Examples of the use of Reissert type chemistry and an unusual reaction with cyanide ion are described below. 

Reaction with Cyanide Ion Reaction with Ilalide Ions Reaction with Amines Acetoxylation Reaction with Aromatics Reaction with Olefins Reaction with Ketones... 

Aryl halides are inert to reaction with cyanide ion under normal Sn2 conditions (chap. 2, sec. 2.11), but they do reaet when heated with cuprous salts like cuprous cyanide (CuCN). Reaction of 1-bromonaphthalene (13) with CuCN at 202°C gave an 89% yield of the aryl nitrile (14). This transformation is called the Rosenmund-von Braun reaction and can be applied to a wide range of aryl halides. The aryl nitriles produced can be used in a variety of reactions. This transformation does not work when potassium or sodium cyanide is used. An amine base is usually added to facilitate the reaction. 

The synthetically useful 5,6-dihydropyridinium salts (102) are readily prepared by the reaction of tetrahydropyridine iV-oxides with trifluoroacetic anhydride. They undergo reaction with cyanide ion at position 2 and with various sulphur and nitrogen nucleophiles at position 4 (Scheme 39)." ... 

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