17658-19-4Relevant academic research and scientific papers
Hydrogenation of heteroaromatic nitriles and aromatic dinitriles by heterogeneous or homogeneous ruthenium catalysts derived from [Ru3(CO)12]
García, Juventino J.,Pérez-Lezama, Nora,Arévalo, Alma
, p. 55 - 58 (2017/05/05)
The use of the complex [Ru3(CO)12] (1) as a catalyst precursor (0.1?mol%) at 200?°C, 60?psi of H2, along with triphenylphosphine (TPP) generated ruthenium nanoparticles (Ru-Nps); this occurred in the presence of pyridine-nitriles leading to a variety of hydrogenation (secondary amine, imine, or imidazole) products, depending of the pyridine-nitrile used, under similar reaction conditions. This relates to relatively good to modest yields, determined by the substituents in the corresponding pyridine. In sharp contrast, the use of aromatic dinitriles did not generate Ru-Nps at 140?°C, 150?psi of H2 and TPP, but allowed the homogeneous catalytic hydrogenation of the 1,4- and 1,3-dicyanobenzenes, to yield the corresponding CN-substituted secondary amine or imine. The main products were characterized by different analytical methods and spectroscopic techniques.
Intramolecular 1,3-Dipolar Cycloaddition of Stabilized Azomethine Ylides to Unactivated Dipolarophiles
Henke, Brad R.,Kouklis, Andrew J.,Heathcock, Clayton H.
, p. 7056 - 7066 (2007/10/02)
The scope and limitations of the intramolecular 1,3-dipolar cycloaddition of doubly-stabilized azomethine ylides to unactivated olefinic, acetylenic, and aromatic dipolarophiles is reported.The azomethine ylides studied were generated by flash vacuum pyrolysis of their corresponding aziridines and were found to add stereospecifically in good to excellent yields to a variety of unactivated dipolarophiles.Generation of the diazabicyclooctane (e.g., 15a,b), diazabicyclononane (e.g., 4, 13), and diazabicyclodecane (e.g., 15c) ring systems are possible using this technology.In addition, the first examples of cycloaddition of a stabilized azomethine ylide to benzene dipolarophiles are reported.Cycloadditions of this type generate highly functionalized tricyclic systems with complete relative stereocontrol at the newly formed stereocenters (e.g., 24-26).Finally, it has been shown that cycloadducts 31 and 32 are in equilibrium, presumably by way of the intermediate azomethine ylide 33, under conditions of flash vacuum pyrolysis.
