Additions to Nitriles

Reactions of organomagnesium and organolithium compounds with nitriles normally proceed via initial addition to the carbon-nitrogen triple bond or via initial a-deprotonation  

The addition reaction is most commonly used for the synthesis of 

In general, the cyano group is less reactive towards organomagnesium compounds than carbonyl groups [A], but more reactive than epoxides [3], 

By far the most common application of the addition reaction is the synthesis of ketones, by hydrolysis of the intermediate imine in situ. Some examples are listed in Table 5.3, and a procedure is given for an intramolecular version. Numerous examples have been tabulated [A]. 

Synthesis of ketones via addition of organomagnesium compounds to nitriles 

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Methyl-17/-l,5-benzodiazepin-2(37/)-one undergoes addition to nitrile imines at the 4,5-bond, e.g. formation of 33.-10 1... 

This fact gives enough reason to suppose that the reaction of hydrogen sulfide addition to nitrile groups starts with the attack of the nucleophilic mercapto anion... 

Larock et al. reported the palladium-catalyzed reactions of alkynes and nitriles with 2-iodophenyl group (Equations (116)-(118)).473,473a 473c Ketones and naphthylamines are obtained presumably through the formation of vinylpalladium species followed by their addition to nitriles to afford palladium imine intermediates. 

Cadmium oxide is used in storage battery electrodes. Its solution, mixed with sodium cyanide, is used in electroplating baths. Other uses are in PVC heat stabilizers as an additive to nitrile rubbers and plastics to improve heat resistance and in ceramic glazes and phosphors. 

Azirines are also made by carbene addition to nitriles (89 — 90) and by thermal or photochemical (68JA2869) elimination of N2 from vinyl azides (e.g. 91 — 92). Vinyl azides are prepared by the Hassner reaction (68JOC2686, 71ACR9), where iodine azide is first added to an alkene and the resultant (3-iodoazide is dehydrohalogenated with base (Scheme 37) (86RTC456). 

Hydroperoxide anion addition to nitrile Preliminary examination ... 

Direct addition of RMgBr or RLi to esters does not give ketones (see below) but addition to nitriles does6 (chapter 13). 

Compounds with carbon-nitrogen multiple bonds were also successfully used in the Barbier procedure. Allylic groups add to imines in high yields (> 77% in the examples published), even enolizable substrates, possibly due to the low basicity of the medium.37 Additions to nitriles occur in THF in the presence of the zinc-silver couple.38 Terpenic ketones were prepared by this method. 

The survey in Figure 7.1 has already shown that nucleophiles can add to nitriles and thus produce carboxylic acid derivatives. Water as a nucleophile either undergoes clean addition to nitriles, and thus produces primary amides (corresponding to a partial hydrolysis of the nitrile ), or it continues with hydrolyzing the amides in situ to give carboxylic acid or carb-oxylate, which would amount to a total hydrolysis of the nitrile ... 

Addition to nitriles.1 Reaction of Cp2Ti=CH2, readily formed from the ti-tanacyclobutane 1, with pivalonitrile forms the [2 + 2]cycloadduct a, which on further reaction with a nitrile forms eventually a new metallacycle 2. This product on acidolysis provides the ft-keto enamine 3. 

They have been suggested as intermediates in acid-catalysed additions to nitriles. The hydration of nitriles probably involves initial protonation of the N end of the —C=N bond, as indicated by the nature of the product of the acid-catalysed reaction between acetonitrile and ethanol (Hill and Rabinowitz, 1926) (equation 36). 

Addition to nitriles 1.5.6.1 Protonation of alkali-metal germanides ... 

The formation of organic azides by the addition of a preformed azide moiety to unsaturated systems seemed until recently to be unpromising as a synthetic procedure and consequendy received scant attention. For example, simple alkenes were found to be inert towards hydrazoic acid in the conditions used by early workers , and additions to nitrile - and thione functions led to the... 

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