3-Aminonitriles special

Preparation of optically active P-aminoesters, P-aminonitriles, and P-aminocarbox-amides are of special relevance for the synthesis of enantiomerically pure P-aminoacids compounds of special relevance in several areas of medicinal chemistry. The resolution of P-aminoesters can be carried out by acylation of the amino groups or by other biocatalytic reactions of the ester groups, such as hydrolysis, transesterification, or aminolysis. The resolution of ethyl ( )-3-aminobutyrate... 

In the special case of a low, continuous flow of ammonia, this process allows the formation of substantial amounts of AA by displacement of the cyanohydrin-aminonitrile equilibrium. The cyanohydrin form can be consid-... 

Note Most of the available examples in this subcategory involve the somewhat specialized condensation of a-aminonitriles (as four-atom synthons)with oxalyl chloride, operating not as a dihalogenoethane derivative (as exemplified previously) but as an a-chloro carboxylic acid derivative. 

In contrast to that, nucleophilic substitution in a-position to nitrogen by cyanide or methoxide predominates, if the electrolysis is carried out in acetonitrile or methanol in presence of cyanide [49], respectively, in basic methanol [50,51]. This reaction, which is supposed to occur via the iminium ion, is interesting for application in organic synthesis. The formation of synthetically valuable o -aminonitriles from 7V,7V-dialkylani-lines has been reported by Andreades and Zahnow [49]. More recently, a series of papers was published by Hurvois, Moinet, Tallec, et al. on the anodic a-cyanation of A-sub-stituted 1-benzazepines, tetrahydroquinolines, and piperidines [Eq. (9)] [52]. The reactions were performed in a special flow-through cell. In the case of the 3-methyl-substituted benzazepines the reaction is stereospecific, leading only to the trans-a-cyano diastereomer. 

Formation of exocyclic iminium ions can be achieved under special circumstances where a functionality other than hydrogen is lost during the elimination step. One version of this technique takes advantage of the fact that carboxylic acid esters are readily hydrolyzed to the parent acids during iV-oxide formation with hydrogen peroxide. Thus, on sequential treatment of the A/-oxide (19) with hydrogen peroxide, trifluoroacetic acid and potassium cyanide the exocyclic, rather than the endocyclic, aminonitrile (20) is produced in 48% yield (equation 9). ... 

In addition to several general reviews on enamine chemistry, all of which include heterocyclic syntheses, there is an extensive survey by Hickmott which is entirely concerned with the formation of heterocycles. More specialized reviews deal with heterocyclic enamines, enaminones, the photochemistry of enamides , heterocyclic jS-enamino esters , enamino thiones , the synthesis of indole alkaloids via enamines , formation of pyrimidines, pyridopyrimidines, pyridines and pyrrolizines from enamines , synthesis of lactams , formation of heterocycles from cyclic enamino ketones and 2-acetylcyclohexen-l-ones, the synthesis of 3-cyano-2(l -pyrimidine-thiones and -selenones from jS-enamino ketones and the chemistry of cyclic en-aminonitriles. ... 

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