Conjugated nitrile

F. F. Fleming, Q. Wang, Unsaturated Nitriles Conjugate Additions of Carbon Nucleophiles to a Recalcitrant Class of Acceptors, Chem. Rev. 2003, 103, 2035-2077. 

C N Intensity strong Nitriles conjugated with double bonds absorb at lower end of frequency range nonconjugated nitriles appear at upper end of range. 

Electron sinks are more varied in nature than electron sources (several are shown in Table A5.1). Anything with a positive charge and/or an empty orbital is an electron sink. Carbocations, Lewis acids, and metal cations are good electron sinks. Atoms involved in ct bonds can also be electron sinks. The proton in a Bronsted acid or weak single bonds between pairs of heteroatoms often act as sinks. Atoms on the partial positive end of polarized bonds are common electron sinks—namely, the carbons in carbonyls, nitriles, conjugate acceptors, and alkyl halides. All of these sinks are also electrophiles. 

Tertiary amines capable of eliminating a secondary amine to form a conjugated system can react with hydrogen cyanide to form y-keto nitriles by amine replacement. Thus (I) yields p-benzoylpropionitrile (IV) ... 

The addition of active methylene compounds (ethyl malonate, ethyl aoeto-acetate, ethyl plienylacetate, nltromethane, acrylonitrile, etc.) to the aP-double bond of a conjugated unsaturated ketone, ester or nitrile In the presence of a basic catalyst (sodium ethoxide, piperidine, diethylamiiie, etc.) is known as the Michael reaction or Michael addition. The reaction may be illustrated by the addition of ethyl malonate to ethyl fumarate in the presence of sodium ethoxide hydrolysis and decarboxylation of the addendum (ethyl propane-1 1 2 3-tetracarboxylate) yields trlcarballylic acid ... 

Note 1. No cyanide was used to remove the copper salts, since the nitrile is probably very base-sensitive (isomerization to a conjugated diene). 

Allylic amine is a less reactive leaving group[7], but the allylic ammonium salts 214 (quaternary ammonium salts) can be used for allylalion(l30,131]. Allylic sulfonium salts are also used for the allylation[130]. The allylic nitrile in the cyclic aminonitrile 215 can be displaced probably via x-allylic complex formation. The possibility of the formation of the dihydropyridinium salts 216 and subsequent conjugate addition are less likelyfl 32],... 

C N 2260-2240 (vs) 2234-2200 (vs) 840-800 (s-vs) 385-350 (m-s) 200-160 (vs) Unsaturated nonaryl substituents lower the frequency and enhance the intensity. Lowered ca 30 cm with aryl and conjugated aliphatics CCCN symmetrical stretching Aliphatic nitriles... 

Conjugate bases of relati-.- ly strong carbon acids like esters and nitriles react with oxiranes. The former give lactones (Scheme 56) (64HC(19-1)418) while the latter provide a route to cyclobutanes (Scheme 57) (74JA5270). 

Conjugated with Nitrile, Nitro, or Sulfone Groups... 

Spectroscopic investigation of enamines conjugated with ketone, ester and nitrile groups established the prevalence of enamine rather than imine-enol tautomers in examples of secondary amines (206-212). Similar studies have been made with enamines of acylpyridines and acetophenones (213,214). 

The cyclizations of conjugated nitrile ylides forming substituted oxazoles and thiazoles were computed up to the MP4/6-31H-G level [OOJOC47]. Relative to 23, oxazole-4-carboxylic acid24 is stabilized by about -38.1 kcal/mol (Scheme 18). 

Enamines react with acceptor-substituted alkenes (Michael acceptors) in a conjugate addition reaction for example with o ,/3-unsaturated carbonyl compounds or nitriles such as acrylonitrile 8. With respect to the acceptor-substituted alkene the reaction is similar to a Michael addition ... 

Formal oxidation of pyrrolidine to the succinimide stage affords a series of compounds used as anticonvulsant agents for treatment of seizures in petit mal epilepsy. Knoevnagel condensation of benzaldehyde with ethyl cyanoacetate affords the unsaturated ester, 9. Conjugate addition of cyanide ion leads to the di-nitrile ester (10). Hydrolysis in mineral acid affords the succinic acid (11), presumably by decarboxylation of the intermediate tricarboxyllie acid. Lactamization with methylamine gives phensuximide (12). ... 

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