New Insights into the Reaction Capabilities of Ionic Organic Bases in Cu-Catalyzed Amination was written by Lo, Quintin A.;Sale, David;Braddock, D. Christopher;Davies, Robert P.. And the article was included in European Journal of Organic Chemistry in 2019.Application In Synthesis of 4-(Benzylamino)benzonitrile This article mentions the following:
The application of ionic organic bases in the copper-catalyzed amination reaction (Ullmann reaction) has been studied at rt, with sub-mol-% catalyst loadings, and with amines at elevated temperatures The cation present in the base has been shown to have little effect on the reaction at standard catalyst and ancillary ligand loadings, whereas the choice of anion is crucial for good reactivity. A substrate scope carried out at rt with the best performing bases, TBAM (bis[tetrabutylammonium]malonate) and bis(tetra-(n-butyl)phosphonium) malonate (TBPM), showed both bases to be highly effective under these mild reaction conditions. Moreover, under sub-mol % catalyst loadings and rt conditions, TBPM gave good yields for a number of different amines and aryl iodides. By using more forceful conditions (120°) moderate to excellent yields of cross-coupled products. As part of this work a study on the stability of the organic bases at 120° was undertaken. TBAM is shown to decompose to give nBu3N and mono-butylmalonate at higher temperatures, and this can be correlated to a decrease in performance in the coupling reaction. The phosphonium cations in TBPM did not undergo analogous reactivity but were shown instead to experience some degree of deprotonation at the α-CH2 to generate phosphonium ylides. This however did not lead to a significantly degradation in the activity of the TBPM in the cross-coupling reaction. In the experiment, the researchers used many compounds, for example, 4-(Benzylamino)benzonitrile (cas: 10282-32-3Application In Synthesis of 4-(Benzylamino)benzonitrile).
4-(Benzylamino)benzonitrile (cas: 10282-32-3) belongs to nitriles. Nitrile carbon shifts are in the range of 115–125 ppm whereas in isonitriles the shifts are around 155–165 ppm. Nitriles are susceptible to hydrogenation over diverse metal catalysts. The reaction can afford either the primary amine (RCH2NH2) or the tertiary amine ((RCH2)3N), depending on conditions.Application In Synthesis of 4-(Benzylamino)benzonitrile
Referemce:
Nitrile – Wikipedia,
Nitriles – Chemistry LibreTexts