Nitriles with carbonyls

IV. REACTIONS OF NITRILES WITH CARBONYL COMPOUND DERIVATIVES... 

The reactions of nitriles with carbonyl compound derivatives have not been sufficiently investigated so far. Some papers, for example, describe the cyclizations of Af-acylena-mines 230 and 232 to pyrimidines 231129 and quinazoline derivatives 233130 (equation 66 see also Reference 67 and equation 28). 

A ketone results from the reaction between a Grignard reagent and a nitrile, with the C=N carbon of the nitrile becoming the carbonyl carbon. Identify the two groups attached to the carbonyl carbon atom in the product. One will come from the Grignard reagent, and the other will come from the nitrile. 

The addition reaction of enolates and enols with carbonyl compounds is of broad scope and of great synthetic importance. Essentially all of the stabilized carbanions mentioned in Section 1.1 are capable of adding to carbonyl groups, in what is known as the generalized aldol reaction. Enolates of aldehydes, ketones, esters, and amides, the carbanions of nitriles and nitro compounds, as well as phosphoms- and sulfur-stabilized carbanions and ylides undergo this reaction. In the next section we emphasize the fundamental regiochemical and stereochemical aspects of the reactions of ketones and aldehydes. 

Double bonds conjugated with aromatic rings and with carbonyl, carboxyl, nitrile and other functions are readily reduced by catalytic hydrogenation and by metals. These reductions are discussed in the appropriate sections aromatics, unsaturated aldehydes and ketones, unsaturated acids, their derivatives, etc. 

The complex hydride reductions of nitriles to aldehydes compare favorably with the classical Stephen reduction which consists of treatment of a nitrile with anhydrous stannous chloride and gaseous hydrogen chloride in ether or diethylene glycol and applies to both aliphatic and aromatic nitriles [183,285, 1152]. An advantage of the Stephen method is its applicability to polyfunctional compounds containing reducible groups such as carbonyl that is reduced by hydrides but not by stannous chloride [1153]. 

The physical and chemical properties of the X -phosphorins 118 and 120 are comparable to those of phosphonium ylids which are resonance-stabilized by such electron-pulling groups as carbonyl or nitrile substituents Thus they can be viewed as cyclic resonance-stabilized phosphonium ylids 118 b, c, d). As expected, they do not react with carbonyl compounds giving the Wittig olefin products. However, they do react with dilute aqueous acids to form the protonated salts. Similarly, they are attacked at the C-2 or C-4 positions by alkyl-, acyl- or diazo-nium-ions Heating with water results in hydrolytic P—C cleavage, phosphine oxide and the hydrocarbon being formed. 

In addition to the reaction of amino groups with carbonyl compounds, in another useful method for the preparation of imines the reduction or condensation of nitriles with other reagents is employed (Eq. 2). Other more specialized methods [lb] are described in Section 5. 

Cleavage of epoxidesThe aiiion (2) of 1 reacts with carbonyl compounds to give a,/(-unsaturated nitriles and LiOSi(CH3)3, as expected.2 The reaction with epoxides is unexpected the products are y-trimethylsilyloxynitriles, which are useful precursors to -/-lactones (equation I). The formulation indicates that a 1,4-migration of the trimethylsilyl group is involved.2... 

Specific adsorbents with electron densities on surface. Graphitized carbon blacks with dense monolayers of Group B molecules or macromolecules deposited on surface. Adsorbents with a functional group, for example, cyano, nitrile, or carbonyl, would also be included in this category. 

Nitriles were also obtained in the reaction of aldoximes with - N,N-diethylamino)propyne via the supposed formation of Ovinyloxime 146 (Scheme 72) (77S338). In both cases, the intermediate O-vinyloximes (145,146), instead of pyrrolization, prefer decomposition into nitrile and carbonyl compounds. 

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