Iminonitrile imine

Photolysis of the pyrazole-4-carboxyaldehyde 169 has been found to afford imidazole 172. This reaction is analogous to the isoxazole-oxazole photoisomerization discussed above. It is most likely that a 1,5-electrocyclic ring closure of iminonitrile imine 171 is responsible for imidazole formation. ... 

In 1904, Jocelyn Field Thorpe and co-workers conducted the first studies of the intermolecular dimerization of nitriles. A short time later, the first example of a dinitrile cyclization was described by Moore and Thorpe. Initially, all products of dinitrile cyclization reactions were characterized as imines. However, in 1955, it was determined that the product of the cyclization of adiponitrile was in actuality an enamine. The enamine structure for the product of dinitrile cyclizations has since been confirmed through numerous other studies, and makes sense chemically. The conjugated enamine would be expected to be more stable than the corresponding nonconjugated P-iminonitrile. 

Methyl has been proved as a practical carbon source of cyano groups. Jiao and co-workers developed a transition-metal-ffee transformation of methyl imines [123]. They employed PIDA as the oxidant and 2 equiv. of NaBr as additive. A variety of methyl imines 11 prepared by the condensation of anilines and acetophenones could work under the optimized condition to give a-iminonitriles 12 (Scheme 4.25). On the aromatic ring of acetophenones, for example, many electron-donating and—withdrawing groups were tolerated (13-15, 17-20). 

Scheme 4.25 Direct transformation of methyl imines to a-iminonitriles...

Zong H, Huang H, Liu J, Bian G, Song L (2012) Added-metal-free catalytic nucleophilic addition of grignard reagents to ketones. J Org Chem 77(10) 4645 652 Chen F, Huang X, Cui Y, Jiao N (2013) Direct transformation of methyl imines to a-iminonitriles under mild and transition-metal-free conditions. Chem Fur J 19(34) 11199-11202... 

The regioselectivity and reactivity of the 1,3-dipolar cycloaddition reactions of nitril-imines with acrylonitrile and methyl acrylate have been investigated. The 1,3-dipolar cycloaddition reactions of nitrilimines with isatin imines yielded spiro[indolin-3,3 -1,2,4-triazol] derivatives under classical and microwave conditions/ An extensive study of the 1,3-dipolar cycloaddition reactions of nitrilimines with a,/ -unsaturated lactones, thiolactones, and lactams has been presented. In all cases, regioisomeric mixtures were obtained with the 5-substituted pyrazole as the major cycloadduct. me5 o-Tetrakis(pentafluorophenyl)porphyrin (51) reacts with iminonitriles (52) yielding pyrazolin-fused chlorines (53) via a 1,3-dipolar cycloaddition reaction (Scheme 17). ... 

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See also in sourсe #XX -- [ ]

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